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# EuroBERT: Scaling Multilingual Encoders for European Languages

Nicolas Boizard, Hippolyte Gisserot-Boukhlef, Duarte M. Alves, André F T Martins, Ayoub Hammal, Caio Corro, Céline Hudelot, Emmanuel Malherbe, Etienne Malaboeuf, Fanny Jourdan, et al.

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## To cite this version:

Nicolas Boizard, Hippolyte Gisserot-Boukhlef, Duarte M. Alves, André F T Martins, Ayoub Hammal, et al.. EuroBERT: Scaling Multilingual Encoders for European Languages. COLM 2025 - Second Conference on Language Modeling, Oct 2025, Montreal, Canada. pp.1-28. hal-05226285

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https://hal.science/hal-05226285v1

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arXiv:2503.05500v2 [cs.CL] 26 Mar 2025

# EuroBERT: Scaling Multilingual Encoders for European Languages

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Nicolas Boizard<sup>1,3</sup> Hippolyte Gisserot-Boukhlef<sup>2,3</sup> Duarte M. Alves<sup>4,5</sup>

André Martins<sup>† 4,5,6</sup> Ayoub Hammal<sup>† 7,8,9</sup> Caio Corro<sup>† 8,10,11</sup> Céline Hudelot<sup>† 3</sup>

Emmanuel Malherbe<sup>† 2</sup> Etienne Malaboeuf<sup>† 12</sup> Fanny Jourdan<sup>† 13</sup> Gabriel

Hautreux<sup>† 12</sup> João Alves<sup>† 6</sup> Kevin El-Haddad<sup>† 1,17</sup> Manuel Faysse<sup>† 3,14</sup> Maxime

Peyrard<sup>† 8,15</sup> Nuno M. Guerreiro<sup>† 3,4,5,6</sup> Patrick Fernandes<sup>† 4,5,18</sup> Ricardo Rei<sup>† 6</sup>

Pierre Colombo<sup>*</sup><sup>3,16</sup>

<sup>1</sup>Diabolocom, <sup>2</sup>Artefact Research Center, <sup>3</sup>MICS, CentraleSupélec, Université Paris-Saclay, <sup>4</sup>Instituto Superior Técnico & Universidade de Lisboa (Lisbon ELLIS Unit), <sup>5</sup>Instituto de Telecomunicações, <sup>6</sup>Unbel, <sup>7</sup>Université Paris-Saclay, <sup>8</sup>CNRS, <sup>9</sup>LISN, <sup>10</sup>INSA Rennes, <sup>11</sup>IRISA, <sup>12</sup>CINES, <sup>13</sup>IRT Saint Exupéry, <sup>14</sup>Illuin Technology, <sup>15</sup>Université Grenoble Alpes, Grenoble INP, LIG, <sup>16</sup>Equall, <sup>17</sup>ISIA Lab, <sup>18</sup>Carnegie Mellon University

**Equal contribution**, †Ordered alphabetically by the first name, *Senior advisor*

General-purpose multilingual vector representations, used in retrieval, regression, and classification, are traditionally obtained from bidirectional encoder models. Despite their wide applicability, encoders have been recently overshadowed by advances in generative decoder-only models. However, many innovations driving this progress are not inherently tied to decoders. In this paper, we revisit the development of multilingual encoders through the lens of these advances, and introduce EuroBERT, a family of multilingual encoders covering European and widely spoken global languages. Our models outperform existing alternatives across a diverse range of tasks, spanning multilingual capabilities, mathematics, and coding, and natively support sequences of up to 8,192 tokens. We also examine the design decisions behind EuroBERT, offering insights into our dataset composition and training pipeline. We publicly release the EuroBERT models, including intermediate training checkpoints, together with our training framework.

Contact: firstname.lastname@centralesupelec.com, duartemalves@tecnico.ulisboa.pt

Website: https://huggingface.co/EuroBERT

Date: March 10, 2025

## 1 Introduction

Many important tasks in Natural Language Processing (NLP), including information retrieval, classification, or regression, are built upon general-purpose vector representations. These representations are traditionally obtained from *bidirectional* encoder models, which aggregate information from the left and right contexts of each token (Devlin et al., 2019; Conneau et al., 2020; He et al., 2023). In contrast, recent advances in generative modeling have shifted the research community's attention towards *unidirectional* architectures (Bai et al., 2023; Llama Team, 2024; OLMo et al., 2025). Notably, these efforts have identified several key performance drivers that span architectural advances, data improvements, and increased scale. Yet, despite no apparent barrier to transferring these insights to *bidirectional* architectures, little effort has been devoted towards this objective, forcing practitioners to depend on outdated models.

In this paper, we introduce a refreshed recipe for training general-purpose multilingual encoders, resulting in the EuroBERT family. Drawing inspiration from recent progress in decoder models, our models feature an updated architecture (§2.1), and are trained on a 5T-token multilingual dataset, covering widely spoken European and global languages,
<figure><img src="image_5.png" /><figcaption>Figure 1: Pareto plots for multilingual tasks (top), showing retrieval performance on MIR-ACL and sentence classification on XNLI, and for math and code tasks (bottom), featuring CodeSearchNet and MathShepherd. The shaded regions indicate the Pareto frontiers.</figcaption></figure>

along with mathematics and code (§2.2). We adopt a masked language modeling objective, and employ a two-phase training pipeline, adjusting the data distribution in the second training phase to improve downstream performance (§2.3).

We extensively evaluate the EuroBERT models, comparing with similarly sized alternatives across a suite of tasks representative of real-world encoder applications (§3). Our models match or exceed the performance of alternative models, such as XLM-RoBERTa (Conneau et al., 2020) and mGTE-MLM (Zhang et al., 2024), on multilingual retrieval, classification and regression tasks, and outperform them on code and mathematics tasks (Figure 1).

We also examine the impact of our design choices through systematic ablations on several components of our annealing recipe (§4). We explore the choice of masking ratio, showing that while higher masking ratios benefit retrieval tasks, lower ratios improve sentence classification. Additionally, we highlight that including data for code and mathematics improves multilingual retrieval, but degrades classification accuracy. Contrary to expectations, we also observe that only selecting documents with high educational value degrades performance, and that instead encoders benefit from a broader range of data sources.

Accompanying this work, we release the EuroBERT family, comprising three models with 210M, 610M and 2.1B parameters. To facilitate future research, we also release intermediate training checkpoints, as well as our training framework.

## 2 EuroBERT: A Refreshed Multilingual Encoder

The EuroBERT models are available in three sizes (210M, 610M, and 2.1B parameters) and closely follow the Llama 3 architecture (Llama Team, 2024) (§2.1). They are trained on a large multilingual corpus, which also includes code and mathematics (§2.2). Their training
pipeline has two stages, pre-training and annealing, and employs the masked language modeling (MLM) objective (S2.3).

## 2.1 Architecture

The EuroBERT models are based on a standard dense transformer (Vaswani et al., 2017), with several architectural changes. Similarly to Llama 2 (Touvron et al., 2023), we remove all biases. Additionally, we incorporate grouped query attention (Ainslie et al., 2023), swish gated linear units (Shazeer, 2020), root mean square layer normalization (Zhang & Sennrich, 2019), and rotary position embeddings (Su et al., 2024).<fnref n="1" />

## 2.2 Dataset

To train EuroBERT, we construct a multilingual 5T-token corpus — 4.8T tokens for pre-training and 200B for annealing — which includes 15 languages: English, French, German, Spanish, Chinese, Italian, Russian, Polish, Portuguese, Japanese, Vietnamese, Dutch, Arabic, Turkish, and Hindi.² Following prior work on curriculum learning (Hu et al., 2024), we adjust the data distribution to emphasize higher-quality datasets during annealing.

**Pre-training mixture.** We use FineWeb (Penedo et al., 2024) for English, and CulturaX (Nguyen et al., 2024) for multilingual data. We also incorporate EuroLLM parallel data (Martins et al., 2024), which can improve cross-lingual transfer (Conneau & Lample, 2019; Reid & Artetxe, 2022; 2023), by concatenating to-English and from-English translation pairs, separated by a special `
` token. Finally, inspired by the benefits of training on code for decoder models (Aryabumi et al., 2024), we add 38 programming languages from The Stack v2 (Lozhkov et al., 2024) and Proof-Pile-2 (Azerbayev et al., 2024), which we find improves multilingual retrieval (S4).

**Annealing mixture.** We classified data not seen during pre-training into four quality levels according to educational value using the EuroLLM classifier (Martins et al., 2024). We then kept the documents above the third threshold which, contrary to our expectations, improved performance on downstream tasks (S4). Additionally, we adjusted the data distribution based on multiple ablations (S4). Specifically, we decreased English while proportionally increasing the remaining languages. We also decreased the amount of code and math while increasing parallel data.³

## 2.3 Training Recipe

**Masked language modeling.** We pre-train EuroBERT models with a 50% masking ratio, following the insights from Wettig et al. (2023), which find that masking 15% and 30% of tokens is sub-optimal, and that larger models benefit from higher masking ratios. For the subsequent annealing, however, we lower the masking ratio to 10% based on downstream evaluations (S4), aligning with the findings from Yang et al. (2023) and Ankner et al. (2024).

**Hyperparameters.** We employed the Warmup-Stable-Decay (WSD) scheduler (Shen et al., 2024), with a linear warm-up phase of 2,000 steps, a constant learning rate of $1 \times 10^{-4}$ during pre-training, and a cosine scheduler decaying to 0 during the annealing phase. During pre-training, we packed sentences to 2,048 tokens and used a Rotary Position Embedding (RoPE) value of 10,000. In the annealing phase, we increased the RoPE theta to 250,000 and randomly cropped our training documents to lengths between 12 and 8,192 tokens. We adopted this approach because, due to pre-processing constraints, our training data had already been segmented into fixed-length documents, making standard variable-length training infeasible. Therefore, we introduced random cropping of these fixed-length

<footnote n="1">¹We provide more architecture details in Appendix A.
²These languages were selected to balance European and widely spoken global languages, and ensure representation across diverse alphabets and language families.
³We provide further details on our pretraining and annealing datasets in Appendix C.</footnote>
sequences as an approximation of variable-length training. Surprisingly, we found that this approach outperforms training only on fixed lengths (§4), further highlighting the necessity for variable length documents during long context training (Gao et al., 2024).

**Infrastructure.** We trained EuroBERT on Adastra, using 92 MI250X GPUs for EuroBERT-210M, 384 MI250X GPUs for EuroBERT-610M, and 96 MI300A GPUs for EuroBERT-2.1B, for a total of 200k GPU hours. Our training framework incorporates FlashAttention (Dao, 2023), fused cross-entropy from LigerKernel (Hsu et al., 2024), `torch.compile` (Ansel et al., 2024), and hybrid sharding with Fully Sharded Data Parallel (Zhao et al., 2023).

# 3 Evaluation

## 3.1 Evaluation Setup

**Datasets and tasks.** We select a suite of tasks to cover various real-world use cases for encoders. For multilingual tasks, we evaluate retrieval using MIRACL (Zhang et al., 2023), MLDR (Chen et al., 2024), WikipediaRetrieval<fnref n="4" />, and CC-News (de Gibert et al., 2024). We assess sentence classification with XNLI (Conneau et al., 2018), PAWS-X (Yang et al., 2019), AmazonReviews (Keung et al., 2020) and MassiveIntent (Keung et al., 2020). Additionally, we evaluate token classification using the NER task from the XGLUE benchmark (Liang et al., 2020). We evaluate sequence regression on the WMT quality estimation task (Bojar et al., 2017; 2018; Barrault et al., 2019; 2020; Akhbardeh et al., 2021; Kocmi et al., 2022), and on summary evaluation using SeaHorse (Clark et al., 2023). For code-related tasks, we evaluate retrieval on CodeSearchNet (Husain et al., 2019) and DupStackMath (Hoogeveen et al., 2015), and classification on CodeDefect (Zhou et al., 2019) and CodeComplexity (Jeon et al., 2023). Finally, in the mathematical domain, we test retrieval on the MathFormula (Drechsel et al., 2025) task, and classification on MathShepherd (Wang et al., 2024b).<fnref n="5" />

**Baselines.** We compare EuroBERT with the multilingual encoders XLM-RoBERTa (Conneau et al., 2020; Goyal et al., 2021), mGTE-MLM (Zhang et al., 2024)<fnref n="6" /> and mDeBERTa-v3. Additionally, for code and mathematical tasks, we compare with the English-only ModernBERT (Warner et al., 2024) models.

**Fine-tuning.** We follow a standardized fine-tuning protocol to ensure fair model comparison. For each task, models are trained for 10,000 steps (unless otherwise specified) on the corresponding training split using a batch size of 32, a 10% warm-up ratio, and a linear learning rate decay. For small datasets requiring multiple epochs, we apply early stopping with a patience of one epoch based on validation performance. To account for model specificities, we fine-tune using 10 logarithmically spaced learning rates (1 × 10⁻<fnref n="5" /> to 1 × 10⁻<fnref n="4" />), selecting the one that achieves the highest validation metric.<fnref n="7" /> For sequence classification, we use the cross-entropy loss during training, while for sequence regression, we substitute it with mean squared error.<fnref n="8" /> For token classification tasks, we use the token-level cross-entropy loss, assigning each sub-token in an entity to the corresponding entity label.<fnref n="9" /> For all retrieval tasks, we finetune for 1,000 steps on MS-MARCO (Bajaj et al., 2016)<fnref n="10" /> using the InfoNCE loss (Oord et al., 2018) with in-batch negatives and cosine similarity.

<footnote n="4">⁴https://huggingface.co/datasets/Samoed/WikipediaRetrievalMultilingual</footnote>

<footnote n="5">⁵We detail the evaluation setup for each task in Appendix D.</footnote>

<footnote n="6">⁶Since the EuroBERT models are general-purpose encoders, we evaluate them against the pre-trained mGTE-MLM variant, which, similarly, was not optimized for retrieval tasks.</footnote>

<footnote n="7">⁷Additional fine-tuning hyperparameters, such as AdamW parameters ($\beta_1$, $\beta_2$, $\epsilon$, and weight decay), are set according to the values reported in the original source papers. For EuroBERT models, we maintain the same settings as those used during pre-training and annealing.</footnote>

<footnote n="8">⁸On summarization (SeaHorse), we train for 5,000 steps to reduce computational costs.</footnote>

<footnote n="9">⁹At inference time, the final label of an entity is determined by majority vote over the sub-tokens.</footnote>

<footnote n="10">¹⁰Since many retrieval datasets lack dedicated training splits, we use MS-MARCO, an English-only dataset. This choice also allows us to assess cross-lingual generalization.</footnote>
<table><caption>Table 1: Results for multilingual tasks, with scores aggregating all languages shown above and scores aggregating European languages in *italic* below. Models are grouped into statistically significant clusters, with best ranked models highlighted in bold.</caption><thead><tr><th rowspan="2">Benchmark</th><th colspan="2">mDeBERTa</th><th colspan="3">XLM-RoBERTa</th><th colspan="3">EuroBERT</th></tr><tr><th>280M</th><th>305M</th><th>280M</th><th>560M</th><th>3.5B</th><th>210M</th><th>610M</th><th>2.1B</th></tr></thead><tbody><tr><td colspan="9" style="text-align:center; font-weight:bold;">Retrieval (nDCG@10)</td></tr><tr><td>MIRACL</td><td>37.56<br>43.75</td><td>91.22<br>93.82</td><td>85.44<br>89.54</td><td>89.43<br>91.63</td><td>91.42<br>92.63</td><td>90.82<br>95.11</td><td>92.62<br>95.01</td><td><b>92.91</b><br>94.81</td></tr><tr><td>MLDR</td><td>18.36<br>20.06</td><td>67.82<br>73.22</td><td>54.65<br>58.75</td><td>60.84<br>65.24</td><td>65.92<br>70.03</td><td>65.43<br>73.42</td><td><b>68.61</b><br>75.81</td><td>66.12<br>72.92</td></tr><tr><td>CC-News</td><td>18.57<br>15.87</td><td>71.34<br>71.54</td><td>61.66<br>60.46</td><td>72.83<br>72.14</td><td><b>80.91</b><br>80.91</td><td>67.25<br>69.04</td><td>75.62<br>76.62</td><td>75.92<br>76.92</td></tr><tr><td>Wikipedia</td><td>57.65<br>58.95</td><td>94.12<br>94.63</td><td>91.04<br>91.74</td><td>93.13<br>93.63</td><td><b>96.31</b><br>96.71</td><td>94.42<br>95.62</td><td><b>95.91</b><br>96.61</td><td><b>95.81</b><br>96.61</td></tr><tr><td colspan="9" style="text-align:center; font-weight:bold;">Sequence Classification (Accuracy)</td></tr><tr><td>XNLI</td><td>79.54<br>82.04</td><td>75.85<br>78.46</td><td>74.16<br>76.67</td><td>81.72<br>84.13</td><td><b>83.71</b><br>86.12</td><td>76.65<br>79.95</td><td>81.93<br>84.72</td><td><b>84.11</b><br>86.81</td></tr><tr><td>PAWS-X</td><td>91.92<br>91.92</td><td>89.83<br>89.83</td><td>88.94<br>88.94</td><td>92.42<br>92.42</td><td><b>92.91</b><br>92.91</td><td>89.93<br>89.93</td><td>92.22<br>92.22</td><td><b>93.01</b><br>93.01</td></tr><tr><td>AmazonReviews</td><td>62.12<br>63.72</td><td>61.53<br>62.73</td><td>61.13<br>62.73</td><td><b>63.11</b><br>64.51</td><td><b>63.61</b><br>64.71</td><td>61.72<br>63.02</td><td>62.62<br>64.02</td><td><b>63.21</b><br>64.51</td></tr><tr><td>MassiveIntent</td><td>86.53<br>87.32</td><td>86.92<br>87.52</td><td>86.33<br>87.22</td><td><b>88.21</b><br>88.81</td><td><b>87.91</b><br>88.51</td><td>86.53<br>87.22</td><td>87.22<br>87.82</td><td>87.52<br>88.22</td></tr><tr><td colspan="9" style="text-align:center; font-weight:bold;">Token Classification (F1 Score)</td></tr><tr><td>NER</td><td><b>96.22</b><br>96.22</td><td>95.26<br>95.26</td><td>95.55<br>95.55</td><td><b>96.12</b><br>96.12</td><td><b>96.32</b><br>96.32</td><td>94.76<br>94.76</td><td>95.94<br>95.94</td><td>95.26<br>95.26</td></tr><tr><td colspan="9" style="text-align:center; font-weight:bold;">Sequence Regression (Spearman)</td></tr><tr><td>WMT (Ref-based)</td><td>45.74<br>46.54</td><td>43.95<br>44.05</td><td>43.06<br>43.16</td><td>45.34<br>45.65</td><td><b>47.72</b><br>48.52</td><td>45.24<br>45.14</td><td>46.03<br>46.54</td><td><b>47.32</b><br>48.52</td></tr><tr><td>WMT (Ref-free)</td><td>42.03<br>41.62</td><td>38.55<br>37.75</td><td>36.57<br>34.26</td><td>40.84<br>39.04</td><td><b>44.51</b><br>44.41</td><td>41.03<br>40.53</td><td>41.53<br>41.13</td><td>38.75<br>38.84</td></tr><tr><td>SeaHorse</td><td>64.25<br>60.35</td><td>63.06<br>59.26</td><td>61.17<br>56.97</td><td>65.54<br>61.44</td><td><b>67.52</b><br>63.32</td><td>63.85<br>60.15</td><td>66.03<br>62.72</td><td><b>67.51</b><br>64.01</td></tr></tbody></table>

**Evaluation metrics.** We report accuracy for sequence classification, Spearman rank correlation for regression, F1 score for token classification, and nDCG@10 for retrieval tasks. We also follow Freitag et al. (2023), and group systems into language-specific clusters based on statistically significant performance gaps at 95% confidence thresholds. We then compute system-level rankings using a normalized Borda count (Colombo et al., 2022), defined as the average over the obtained per-language clusters. Note that a first cluster will only exist if a model significantly outperforms all others on a majority of languages.

## 3.2 Results

Table 1 presents the aggregated results across multilingual tasks, and Table 2 summarizes performance on code and mathematics benchmarks.<fnref n="11" />

**The EuroBERT family delivers strong performance across diverse domains and tasks.** Our largest model, EuroBERT-2.1B, ranks first on 10 out of 18 tasks, competing closely with the larger XLM-RoBERTa-3.5B. EuroBERT-610M is also on part with XLM-RoBERTa-3.5B across several multilingual tasks while being five times smaller, and outperforms it on code

<footnote n="11">¹¹We provide per-language results in Appendix F.</footnote>
<table><caption>Table 2: Results for code and mathematical tasks. Models are grouped into statistically significant clusters, with best ranked models highlighted in bold.</caption><thead><tr><th rowspan="2">Benchmark</th><th colspan="2">ModernBERT</th><th colspan="2">mDeBERTa</th><th colspan="2">mGTE</th><th colspan="3">XLM-RoBERTa</th><th colspan="3">EuroBERT</th></tr><tr><th>150M</th><th>395M</th><th>280M</th><th>305M</th><th>280M</th><th>560M</th><th>3.5B</th><th>210M</th><th>610M</th><th>2.1B</th></tr></thead><tbody><tr><td colspan="11" style="text-align: center; font-weight: bold;">Code Retrieval (nDCG@10)</td></tr><tr><td>CodeSearchNet</td><td>53.95</td><td>65.83</td><td>2.8</td><td>34.07</td><td>23.08</td><td>40.86</td><td>54.15</td><td>58.94</td><td>69.92</td><td>72.61</td></tr><tr><td>DupStackMath</td><td>39.74</td><td>45.52</td><td>10.27</td><td>37.54</td><td>29.36</td><td>36.95</td><td>42.93</td><td>41.73</td><td>46.02</td><td>48.31</td></tr><tr><td colspan="11" style="text-align: center; font-weight: bold;">Code Classification (Accuracy)</td></tr><tr><td>CodeComplexity</td><td>86.13</td><td>88.63</td><td>73.95</td><td>74.55</td><td>74.15</td><td>83.64</td><td>84.34</td><td>91.92</td><td>94.21</td><td>95.21</td></tr><tr><td>CodeDefect</td><td>65.83</td><td>67.02</td><td>64.73</td><td>63.54</td><td>61.94</td><td>54.35</td><td>65.83</td><td>69.51</td><td>69.01</td><td>67.72</td></tr><tr><td colspan="11" style="text-align: center; font-weight: bold;">Math Retrieval (nDCG@10)</td></tr><tr><td>MathFormula</td><td>89.65</td><td>91.92</td><td>85.27</td><td>83.48</td><td>83.18</td><td>81.4</td><td>89.16</td><td>91.53</td><td>92.61</td><td>91.04</td></tr><tr><td colspan="11" style="text-align: center; font-weight: bold;">Math Classification (Accuracy)</td></tr><tr><td>MathShepherd</td><td>77.74</td><td>83.62</td><td>75.15</td><td>77.24</td><td>71.96</td><td>67.67</td><td>82.53</td><td>84.02</td><td>87.31</td><td>86.81</td></tr></tbody></table>

<figure><img src="image_6.png" /><figcaption>Figure 2: Difference in F1 Score between EuroBERT and XLM-RoBERTa by tokenizer fertility (left plot) and fertility distribution for both tokenizers (right plot) on the NER dataset.</figcaption></figure>

and mathematics benchmarks. Likewise, EuroBERT-210M matches XLM-RoBERTa-560M performance while having less than half the parameters, and consistently outperforms other models of similar size, showing especially strong results on European languages.

**EuroBERT is effective at document ranking.** Across domains, EuroBERT consistently ranks high for retrieval tasks. Notably, the 210M and 610M parameter models outperform all models of comparable sizes, and are competitive with the larger XLM-RoBERTa-3.5B.<fnref n="12" />

**EuroBERT models are on par with similarly sized models for sequence classification.** On sequence classification, no model significantly outperforms all others. During the development of EuroBERT, we found that several design decisions lead to a trade-off between retrieval and classification capabilities (§4). We highlight, however, that EuroBERT-2.1B is still among the highest ranking systems, and that the smaller models in the family are competitive with models of comparable size.

**There is room for improvement on token classification.** On the NER task, EuroBERT lags behind XLM-RoBERTa. However, we observed that models achieve comparable F1 scores when splitting entities into a similar number of tokens, as shown in Figure 2. In contrast, models are significantly better when dividing entities into fewer tokens. We posit that token

<footnote n="12">¹²For retrieval, increasing model size did not always lead to better results. Further analysis, in Appendix E, revealed that EuroBERT-2.1B benefits significantly from a more thorough grid search.</footnote>
<figure><img src="image_7.png" /><figcaption>Figure 3: Results by length of the positive documents for retrieval (MLDR) and input documents for summarization (SeaHorse).</figcaption></figure>

classification tasks may benefit from larger vocabularies, with lower fertility, such as the one used in the XLM-RoBERTa family. We also note, however, that increasing the vocabulary size also increases the number of parameters, particularly for smaller models.<fnref n="13" />

**EuroBERT can function as an evaluation metric.** EuroBERT models match or exceed the performance of similarly sized systems in reference-based translation evaluation. For reference-free evaluation, while EuroBERT-2.1B lags behind the larger XLM-RoBERTa, the 210M and 610M variants are competitive with other baselines. In the future, we will explore other training signals to further enhance EuroBERT’s cross-lingual capabilities. For summary evaluation, EuroBERT models consistently outperform similarly sized alternatives.

**EuroBERT maintains performance at longer context lengths.** Figure 3 compares the long context performance of EuroBERT and XLM-RoBERTa. While both models achieve similar performance for shorter inputs, EuroBERT maintains performance at longer contexts, whereas XLM-RoBERTa suffers notable degradation.

**The EuroBERT family excels in tasks related to code and mathematics.** On these tasks in the code and math domain, all EuroBERT models consistently surpass other systems. Notably, EuroBERT-210M reflects most of the performance of the larger models in the family, and ranks above all baselines, highlighting its capabilities at a smaller scale.

# 4 Training Recipe Analysis

We measure the impact of various design decisions made during the development of EuroBERT with extensive ablations. Following Blakeney et al. (2024) and Llama Team (2024), we perform multiple annealing runs on 40B tokens, each varying a different component of our recipe, and measure the performance on the XNLI and MIRACL validation sets, the former representing multilingual classification and the latter multilingual retrieval.<fnref n="14" />

**Balancing the language distribution enhances performance.** The left-most plot in Figure 4 reports retrieval and classification performance as the proportion of English is reduced

<footnote n="13">¹³For example, doubling the vocabulary size of EuroBERT-210M would add 100M parameters to the model embeddings.</footnote>

<footnote n="14">¹⁴We follow the procedure from §3, but instead evaluate on the validation splits considering only European languages.</footnote>
<figure><img src="image_8.png" /><figcaption>Figure 4: Impact of changing data subset ratios during annealing. The first vertical axis in each subplot denotes the *reference* data mix from Table 6.</figcaption></figure>

<figure><img src="image_9.png" /><figcaption>Figure 5: Impact of hyperparameter choices during annealing. The first vertical axis in each subplot denotes the *reference* data mix from Table 6.</figcaption></figure>

and re-distributed between other languages. We observe that a more balanced distribution improves overall results. However, when the language distribution becomes too close to uniform, there is a degradation in performance.

**Including math and code improves multilingual retrieval, but degrades multilingual classification.** The second and third plots in Figure 4 show MIRACL performance dropping and XNLI accuracy rising as the quantity of math and code data decreases. In future work, we will investigate how to better balance downstream task performance during pre-training.

**Increasing parallel data improves multilingual classification and retrieval.** The fourth plot in Figure 4 presents XNLI and MIRACL performance when increasing parallel data. In line with recent work showing the benefits of pre-training with parallel data (Anil et al., 2023; Briakou et al., 2023; Alves et al., 2024), we find it improves both benchmarks.

**Adding instruction fine-tuning data degrades model performance.** The right-most plot in Figure 4 analyses the impact of adding instructions during annealing, which can improve performance for decoder language models (Wei et al., 2022; Chung et al., 2024). In contrast to decoders, it leads to worse performance when training an encoder model.

**Varying sentence length improves performance.** The first plot in Figure 5 examines the impact of variable sentence lengths during annealing. Compared to the fixed packed sentence lengths employed in pretraining, variable sentence lengths significantly boosts XNLI and moderately MIRACL performance.<fnref n="15" /> This improvement remains stable, without degradation when the maximum context length is extended to 8,192 tokens.

**A reduced masking ratio during annealing enhances classification accuracy.** Similarly to previous research advocating a lower masking ratio in later training (Yang et al., 2023;

<footnote n="15">¹⁵We hypothesize this gap stems from the prevalence of shorter sequences in the XNLI dataset.</footnote>
<figure><img src="image_10.png" /><figcaption>Figure 6: Quality buckets for XNLI and MIRACL English training subset.</figcaption></figure>

Ankner et al., 2024), we also find that reducing it to 10% during the annealing phase improves EuroBERT's accuracy on XNLI, though it leads to a decline in MIRACL scores.

**Filtering data based on educational value can degrade results.** Contrary to initial expectations, using the highest quality data bucket during annealing does not result in better performance on XNLI and MIRACL. Instead, as illustrated in the right-most plot of Figure 5, mixing the buckets with quality levels 3 and 4 leads to the best overall results. Curiously, inspecting the evaluation splits of these datasets revealed that our quality filter would discard nearly all examples in XNLI, and many in MIRACL, as shown in Figure 6. This result highlights a potential domain mismatch, wherein our training data deviates from the distribution of downstream tasks. Indeed, while educational value fits assistant-like tasks typically delegated to LLMs, a broader coverage of textual data, reflected in mixing both quality buckets, may be more inline with general-purpose vector representations. In future work, we would like to explore quality filters that are better tailored to encoders.

**Final annealing configuration.** The previous results revealed several design choices that trade off classification and retrieval performance. In the final data mix, we aimed to balance these two tasks. Based on the previous analysis, we created our final annealing dataset by selecting data above the third threshold. We reduced the proportion of English to 26% while proportionally increasing the share of the remaining languages. We allocated 6% and 4% of the data mix to math and code, respectively. Additionally, we increased the proportion of parallel data to 6%, and removed instructions. We finally lowered the masking ratio to 10% and performed annealing with random sentence lengths of up to 8,192 tokens.

# 5 Related Work

Encoder models have shown strong performance in non-generative tasks, such as classification and retrieval (Devlin et al., 2019; Liu et al., 2019; He et al., 2023; Acheampong et al., 2021; Ma et al., 2019; Karpukhin et al., 2020; Wang et al., 2024a). Variants of these models have also extended support to multiple languages and cross-lingual tasks (Conneau et al., 2020). However, scaling to many languages introduces the “curse of multilinguality” (Conneau et al., 2020; Chang et al., 2024), where interference across languages degrades performance. Notably, increasing model capacity has been shown to mitigate this effect (Conneau et al., 2020), motivating our focus on scale.

Encoders are typically trained with masked language modeling (MLM) (Devlin et al., 2019). While alternatives like replaced token detection (He et al., 2023) exist, we adopt the MLM objective because initial evaluations of existing models showed more balanced results across tasks. Building upon the effectiveness of higher masking ratios (Wettig et al., 2023), we mask 50% of the training tokens during pre-training. Prior work has also shown the benefits of decreasing the masking ratio in later phases of training (Yang et al., 2023; Ankner et al., 2024), we also lower our masking ratio to 10% during annealing. Interestingly, we demonstrate that this choice improves classification accuracy, but reduces retrieval quality.
Recent concurrent work, such as ModernBERT (Warner et al., 2024) and mGTE (Zhang et al., 2024), also revisits encoders in light of advances in decoder models. Similar to our approach, they incorporate grouped query attention (Ainslie et al., 2023), rotary positional embeddings (Su et al., 2024), gated linear units (Shazeer, 2020), root mean square layer normalization (Zhang & Sennrich, 2019), and support for longer context windows. However, we additionally draw inspiration from Llama Team (2024); Yang et al. (2024) by including code and mathematical data during pre-training, which we show improves retrieval quality.

# 6 Conclusion

We propose a recipe for training general-purpose multilingual encoders, creating the EuroBERT family. We incorporate recent architectural advances from decoder models, and train on a multilingual dataset containing European and globally spoken languages, together with code and mathematics. Our models outperform existing alternatives on a comprehensive suite of tasks covering multilingual capabilities, mathematics and code. We also extensively analyze the design decisions behind EuroBERT's dataset and training pipeline. Alongside this paper, we release all models in the EuroBERT family, including intermediate training checkpoints, and our training framework to facilitate future research.

# Acknowledgments

We sincerely thank the ADASTRA supercomputer (CINES) for its technical support and high-performance computing (HPC) resources, provided through grants C1615122 and GDA2401. We also appreciate the support of the French government through the France 2030 program as part of the ArGiMi project. This work was also supported by the EU's Horizon Europe Research and Innovation Actions (UTTER, contract 101070631), by the project DECOLLAGE (ERC-2022-CoG 101088763), by the Portuguese Recovery and Resilience Plan through project C645008882-00000055 (Center for Responsible AI), and by FCT/MECI through national funds and when applicable co-funded EU funds under UID/50008: Instituto de Telecomunicações. Duarte was also partially supported by the DataIA Institute, whose contributions facilitated the completion of this work.
References

Francisca Adoma Acheampong, Henry Nunoo-Mensah, and Wenyu Chen. Transformer models for text-based emotion detection: a review of bert-based approaches. *Artificial Intelligence Review*, 54(8), 2021. URL https://dl.acm.org/doi/abs/10.1007/s10462-021-09958-2.

Joshua Ainslie, James Lee-Thorp, Michiel de Jong, Yury Zemlyanskiy, Federico Lebron, and Sumit Sanghai. GQA: Training generalized multi-query transformer models from multi-head checkpoints. In *Proceedings of the 2023 Conference on Empirical Methods in Natural Language Processing*, Singapore, December 2023. Association for Computational Linguistics. URL https://aclanthology.org/2023.emnlp-main.298/.

Farhad Akhbardeh, Arkady Arkhangorodsky, Magdalena Biesialska, Ondřej Bojar, Rajen Chatterjee, Vishrav Chaudhary, Marta R. Costa-jussa, Cristina España-Bonet, Angela Fan, Christian Federmann, Markus Freitag, Yvette Graham, Roman Grundkiewicz, Barry Haddow, Leonie Harter, Kenneth Heafield, Christopher Homan, Matthias Huck, Kwabena Amponsah-Kaakyire, Jungo Kasai, Daniel Khashabi, Kevin Knight, Tom Kocmi, Philipp Koehn, Nicholas Lourie, Christof Monz, Makoto Morishita, Masaaki Nagata, Ajay Nagesh, Toshiaki Nakazawa, Matteo Negri, Santanu Pal, Allahsera Auguste Tapo, Marco Turchi, Valentin Vydrin, and Marcos Zampieri. Findings of the 2021 conference on machine translation (WMT21). In *Proceedings of the Sixth Conference on Machine Translation*, Online, November 2021. Association for Computational Linguistics. URL https://aclanthology.org/2021.wmt-1.1/.

Duarte Miguel Alves, José Pombal, Nuno M Guerreiro, Pedro Henrique Martins, João Alves, Amin Farajian, Ben Peters, Ricardo Rei, Patrick Fernandes, Sweta Agrawal, et al. Tower: An open multilingual large language model for translation-related tasks. In *First Conference on Language Modeling*, 2024. URL https://arxiv.org/abs/2402.17733.

Rohan Anil, Andrew M. Dai, Orhan Firat, Melvin Johnson, Dmitry Lepikhin, Alexandre Passos, Siamak Shakeri, Emanuel Taropa, Paige Bailey, Zhifeng Chen, Eric Chu, Jonathan H. Clark, Laurent El Shafey, Yanping Huang, Kathy Meier-Hellstern, Gaurav Mishra, Erica Moreira, Mark Omernick, Kevin Robinson, Sebastian Ruder, Yi Tay, Kefan Xiao, Yuanzhong Xu, Yujing Zhang, Gustavo Hernandez Abrego, Junwhan Ahn, Jacob Austin, Paul Barham, Jan Botha, James Bradbury, Siddhartha Brahma, Kevin Brooks, Michele Catasta, Yong Cheng, Colin Cherry, Christopher A. Choquette-Choo, Aakanksha Chowdhery, Clément Crepy, Shachi Dave, Mostafa Dehghani, Sunipa Dev, Jacob Devlin, Mark Díaz, Nan Du, Ethan Dyer, Vlad Feinberg, Fangxiaoyu Feng, Vlad Fienber, Markus Freitag, Xavier Garcia, Sebastian Gehrmann, Lucas Gonzalez, Guy Gur-Ari, Steven Hand, Hadi Hashemi, Le Hou, Joshua Howland, Andrea Hu, Jeffrey Hui, Jeremy Hurwitz, Michael Isard, Abe Ittycheriah, Matthew Jagielski, Wenhao Jia, Kathleen Kenealy, Maxim Krikun, Sneha Kudugunta, Chang Lan, Katherine Lee, Benjamin Lee, Eric Li, Music Li, Wei Li, YaGuang Li, Jian Li, Hyeontaek Lim, Hanzhao Lin, Zhongtao Liu, Frederick Liu, Marcello Maggioni, Aroma Mahendru, Joshua Maynez, Vedant Misra, Maysam Moussalem, Zachary Nado, John Nham, Eric Ni, Andrew Nystrom, Alicia Parrish, Marie Pellat, Martin Polacek, Alex Polozov, Reiner Pope, Siyuan Qiao, Emily Reif, Bryan Richter, Parker Riley, Alex Castro Ros, Aurko Roy, Brennan Saeta, Rajkumar Samuel, Renee Shelby, Ambrose Slone, Daniel Smilkov, David R. So, Daniel Sohn, Simon Tokumine, Dasha Valter, Vijay Vasudevan, Kiran Vodrahalli, Xuezhi Wang, Pidong Wang, Zirui Wang, Tao Wang, John Wieting, Yuhuai Wu, Kelvin Xu, Yunhan Xu, Linting Xue, Pengcheng Yin, Jiahui Yu, Qiao Zhang, Steven Zheng, Ce Zheng, Weikang Zhou, Denny Zhou, Slav Petrov, and Yonghui Wu. Palm 2 technical report. arXiv preprint arXiv:2305.10403, 2023. URL https://arxiv.org/abs/2305.10403.

Zachary Ankner, Naomi Saphra, Davis Blalock, Jonathan Frankle, and Matthew Leavitt. Dynamic masking rate schedules for MLM pretraining. In *Proceedings of the 18th Conference of the European Chapter of the Association for Computational Linguistics (Volume 2: Short Papers)*, St. Julian's, Malta, March 2024. Association for Computational Linguistics. URL https://aclanthology.org/2024.eacl-short.42/.
Jason Ansel, Edward Yang, Horace He, Natalia Gimelshein, Animesh Jain, Michael Voznesensky, Bin Bao, Peter Bell, David Berard, Evgeni Burovski, et al. Pytorch 2: Faster machine learning through dynamic python bytecode transformation and graph compilation. In *Proceedings of the 29th ACM International Conference on Architectural Support for Programming Languages and Operating Systems, Volume 2, 2024*. URL https://dl.acm.org/doi/abs/10.1145/3620665.3640366.

Viraat Aryabumi, Yixuan Su, Raymond Ma, Adrien Morisot, Ivan Zhang, Acyr Locatelli, Marzieh Fadaee, Ahmet Üstün, and Sara Hooker. To code, or not to code? exploring impact of code in pre-training. CoRR, abs/2408.10914, 2024. URL https://doi.org/10.48550/arXiv.2408.10914.

Zhangir Azerbayev, Hailey Schoelkopf, Keiran Paster, Marco Dos Santos, Stephen Marcus McAleer, Albert Q Jiang, Jia Deng, Stella Biderman, and Sean Welleck. Llemma: An open language model for mathematics. In *The Twelfth International Conference on Learning Representations*, 2024. URL https://openreview.net/forum?id=4WnqRR915j.

Jinze Bai, Shuai Bai, Yunfei Chu, Zeyu Cui, Kai Dang, Xiaodong Deng, Yang Fan, Wenbin Ge, Yu Han, Fei Huang, Binyuan Hui, Luo Ji, Mei Li, Junyang Lin, Runji Lin, Dayiheng Liu, Gao Liu, Chengqiang Lu, Keming Lu, Jianxin Ma, Rui Men, Xingzhang Ren, Xuancheng Ren, Chuanqi Tan, Sinan Tan, Jianhong Tu, Peng Wang, Shijie Wang, Wei Wang, Shengguang Wu, Benfeng Xu, Jin Xu, An Yang, Hao Yang, Jian Yang, Shusheng Yang, Yang Yao, Bowen Yu, Hongyi Yuan, Zheng Yuan, Jianwei Zhang, Xingxuan Zhang, Yichang Zhang, Zhenru Zhang, Chang Zhou, Jingren Zhou, Xiaohuan Zhou, and Tianhang Zhu. Qwen technical report, 2023. URL https://arxiv.org/abs/2309.16609.

Payal Bajaj, Daniel Campos, Nick Craswell, Li Deng, Jianfeng Gao, Xiaodong Liu, Rangan Majumder, Andrew McNamara, Bhaskar Mitra, Tri Nguyen, et al. Ms marco: A human generated machine reading comprehension dataset. arXiv preprint arXiv:1611.09268, 2016. URL https://arxiv.org/abs/1611.09268.

Loïc Barrault, Ondřej Bojar, Marta R. Costa-jussà, Christian Federmann, Mark Fishel, Yvette Graham, Barry Haddow, Matthias Huck, Philipp Koehn, Shervin Malmasi, Christof Monz, Mathias Müller, Santanu Pal, Matt Post, and Marcos Zampieri. Findings of the 2019 conference on machine translation (WMT19). In *Proceedings of the Fourth Conference on Machine Translation (Volume 2: Shared Task Papers, Day 1)*, Florence, Italy, August 2019. Association for Computational Linguistics. URL https://aclanthology.org/W19-5301/.

Loïc Barrault, Magdalena Biesialska, Ondřej Bojar, Marta R. Costa-jussà, Christian Federmann, Yvette Graham, Roman Grundkiewicz, Barry Haddow, Matthias Huck, Eric Joanis, Tom Kocmi, Philipp Koehn, Chi-kiu Lo, Nikola Ljubešić, Christof Monz, Makoto Morishita, Masaaki Nagata, Toshiaki Nakazawa, Santanu Pal, Matt Post, and Marcos Zampieri. Findings of the 2020 conference on machine translation (WMT20). In *Proceedings of the Fifth Conference on Machine Translation*, Online, November 2020. Association for Computational Linguistics. URL https://aclanthology.org/2020.wmt-1.1/.

Cody Blakeney, Mansheej Paul, Brett W Larsen, Sean Owen, and Jonathan Frankle. Does your data spark joy? performance gains from domain upsampling at the end of training. In *First Conference on Language Modeling*, 2024.

Ondřej Bojar, Rajen Chatterjee, Christian Federmann, Yvette Graham, Barry Haddow, Shujian Huang, Matthias Huck, Philipp Koehn, Qun Liu, Varvara Logacheva, Christof Monz, Matteo Negri, Matt Post, Raphael Rubino, Lucia Specia, and Marco Turchi. Findings of the 2017 conference on machine translation (WMT17). In *Proceedings of the Second Conference on Machine Translation*, Copenhagen, Denmark, September 2017. Association for Computational Linguistics. URL https://aclanthology.org/W17-4717/.

Ondřej Bojar, Christian Federmann, Mark Fishel, Yvette Graham, Barry Haddow, Matthias Huck, Philipp Koehn, and Christof Monz. Findings of the 2018 conference on machine translation (WMT18). In *Proceedings of the Third Conference on Machine Translation: Shared Task Papers*, Belgium, Brussels, October 2018. Association for Computational Linguistics. URL https://aclanthology.org/W18-6401/.
Eleftheria Briakou, Colin Cherry, and George Foster. Searching for needles in a haystack: On the role of incidental bilingualism in PaLM's translation capability. In *Proceedings of the 61st Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers)*, Toronto, Canada, July 2023. Association for Computational Linguistics. URL https://aclanthology.org/2023.acl-long.524/.

Tyler A. Chang, Catherine Arnett, Zhuowen Tu, and Ben Bergen. When is multilingual-ity a curse? language modeling for 250 high- and low-resource languages. In *Proceedings of the 2024 Conference on Empirical Methods in Natural Language Processing, Mi-ami, Florida, USA, November 2024*. Association for Computational Linguistics. URL https://aclanthology.org/2024.emnlp-main.236/.

Jianlyu Chen, Shitao Xiao, Peitian Zhang, Kun Luo, Defu Lian, and Zheng Liu. M3-embedding: Multi-linguality, multi-functionality, multi-granularity text embeddings through self-knowledge distillation. In *Findings of the Association for Computational Lin-guistics: ACL 2024, Bangkok, Thailand, August 2024*. Association for Computational Linguistics. URL https://aclanthology.org/2024.findings-acl.137/.

Hyung Won Chung, Le Hou, Shayne Longpre, Barret Zoph, Yi Tay, William Fedus, Yunxuan Li, Xuezhi Wang, Mostafa Dehghani, Siddhartha Brahma, Albert Webson, Shixiang Shane Gu, Zhuyun Dai, Mirac Suzgun, Xinyun Chen, Aakanksha Chowdhery, Alex Castro-Ros, Marie Pellat, Kevin Robinson, Dasha Valter, Sharan Narang, Gaurav Mishra, Adams Yu, Vincent Y. Zhao, Yanping Huang, Andrew M. Dai, Hongkun Yu, Slav Petrov, Ed H. Chi, Jeff Dean, Jacob Devlin, Adam Roberts, Denny Zhou, Quoc V. Le, and Jason Wei. Scaling instruction-finetuned language models. *J. Mach. Learn. Res.*, 25:70:1–70:53, 2024. URL https://jmlr.org/papers/v25/23-0870.html.

Elizabeth Clark, Shruti Rijhwani, Sebastian Gehrmann, Joshua Maynez, Roee Aharoni, Vitaly Nikolaev, Thibault Sellam, Aditya Siddhant, Dipanjan Das, and Ankur Parikh. SEAHORSE: A multilingual, multifaceted dataset for summarization evaluation. In *Proceedings of the 2023 Conference on Empirical Methods in Natural Language Processing, Singapore, December 2023*. Association for Computational Linguistics. URL https://aclanthology.org/2023.emnlp-main.584.

Pierre Colombo, Nathan Noiry, Ekhine Irurozki, and Stephan Clémençon. What are the best systems? new perspectives on nlp benchmarking. In *Advances in Neural Information Processing Systems, volume 35*. Curran Associates, Inc., 2022. URL https://proceedings.neurips.cc/paper_files/paper/2022/file/ac4920f4085b5662133dd751493946a6-Paper-Conference.pdf.

Alexis Conneau and Guillaume Lample. Cross-lingual language model pretraining. In *Advances in Neural Information Processing Systems, volume 32*. Curran Associates, Inc., 2019. URL https://proceedings.neurips.cc/paper_files/paper/2019/file/c04c19c2c2474dbf5f7ac4372c5b9af1-Paper.pdf.

Alexis Conneau, Ruty Rinott, Guillaume Lample, Adina Williams, Samuel Bowman, Holger Schwenk, and Veselin Stoyanov. XNLI: Evaluating cross-lingual sentence representations. In *Proceedings of the 2018 Conference on Empirical Methods in Natural Language Processing, Brussels, Belgium, October-November 2018*. Association for Computational Linguistics. URL https://aclanthology.org/D18-1269/.

Alexis Conneau, Kartikay Khandelwal, Naman Goyal, Vishrav Chaudhary, Guillaume Wenzek, Francisco Guzmán, Edouard Grave, Myle Ott, Luke Zettlemoyer, and Veselin Stoyanov. Unsupervised cross-lingual representation learning at scale. In *Proceedings of the 58th Annual Meeting of the Association for Computational Linguistics, Online, July 2020*. Association for Computational Linguistics. URL https://aclanthology.org/2020.acl-main.747/.

Tri Dao. Flashattention-2: Faster attention with better parallelism and work partitioning. In *The Twelfth International Conference on Learning Representations, 2023*. URL https://arxiv.org/abs/2307.08691.
Ona de Gibert, Graeme Nail, Nikolay Arefyev, Marta Bañón, Jelmer van der Linde, Shaoxiong Ji, Jaume Zaragoza-Bernabeu, Mikko Aulamo, Gema Ramírez-Sánchez, Andrey Kutuzov, Sampo Pyysalo, Stephan Oepen, and Jörg Tiedemann. A new massive multilingual dataset for high-performance language technologies. In *Proceedings of the 2024 Joint International Conference on Computational Linguistics, Language Resources and Evaluation (LREC-COLING 2024)*, Torino, Italia, May 2024. ELRA and ICCL. URL https://aclanthology.org/2024.lrec-main.100/.

Jacob Devlin, Ming-Wei Chang, Kenton Lee, and Kristina Toutanova. BERT: Pre-training of deep bidirectional transformers for language understanding. In *Proceedings of the 2019 Conference of the North American Chapter of the Association for Computational Linguistics: Human Language Technologies, Volume 1 (Long and Short Papers)*, Minneapolis, Minnesota, June 2019. Association for Computational Linguistics. URL https://aclanthology.org/N19-1423/.

Jonathan Drechsel, Anja Reusch, and Steffen Herbold. MAMUT: A novel framework for modifying mathematical formulas for the generation of specialized datasets for language model training, 2025. URL https://arxiv.org/abs/2502.20855.

Markus Freitag, Nitika Mathur, Chi-kiu Lo, Eleftherios Avramidis, Ricardo Rei, Brian Thompson, Tom Kocmi, Frederic Blain, Daniel Deutsch, Craig Stewart, Chrysoula Zerva, Sheila Castilho, Alon Lavie, and George Foster. Results of wmt23 metrics shared task: Metrics might be guilty but references are not innocent. In *Proceedings of the Eighth Conference on Machine Translation*, Singapore, December 2023. Association for Computational Linguistics. URL https://aclanthology.org/2023.wmt-1.51.

Tianyu Gao, Alexander Wettig, Howard Yen, and Danqi Chen. How to train long-context language models (effectively). *arXiv preprint arXiv:2410.02660*, 2024. URL https://arxiv.org/abs/2410.02660.

Naman Goyal, Jingfei Du, Myle Ott, Giri Anantharaman, and Alexis Conneau. Larger-scale transformers for multilingual masked language modeling. In *Proceedings of the 6th Workshop on Representation Learning for NLP (RepL4NLP-2021)*, Online, August 2021. Association for Computational Linguistics. URL https://aclanthology.org/2021.repl4nlp-1.4/.

Pengcheng He, Jianfeng Gao, and Weizhu Chen. Debertav3: Improving deberta using electra-style pre-training with gradient-disentangled embedding sharing. In *The Eleventh International Conference on Learning Representations*, 2023. URL https://arxiv.org/abs/2111.09543.

Doris Hoogeveen, Karin M Verspoor, and Timothy Baldwin. Cqadupstack: A benchmark data set for community question-answering research. In *Proceedings of the 20th Australasian document computing symposium*, 2015. URL https://dl.acm.org/doi/abs/10.1145/2838931.2838934?casa_token=-tk7Uh-Jal4AAAAA:LP908GQ05y0QAW6m4nw81fVeZspyMSSae4QXz7vStNi-zdy6MNAEw393sY0kWvDZfD07PwnKeHpX5A.

Pin-Lun Hsu, Yun Dai, Vignesh Kothapalli, Qingquan Song, Shao Tang, Siyu Zhu, Steven Shimizu, Shivam Sahni, Haowen Ning, and Yanning Chen. Liger kernel: Efficient triton kernels for llm training, 2024. URL https://arxiv.org/abs/2410.10989.

Shengding Hu, Yuge Tu, Xu Han, Ganqu Cui, Chaoqun He, Weilin Zhao, Xiang Long, Zhi Zheng, Yewei Fang, Yuxiang Huang, Xinrong Zhang, Zhen Leng Thai, Chongyi Wang, Yuan Yao, Chenyang Zhao, Jie Zhou, Jie Cai, Zhongwu Zhai, Ning Ding, Chao Jia, Guoyang Zeng, dahai li, Zhiyuan Liu, and Maosong Sun. MiniCPM: Unveiling the potential of small language models with scalable training strategies. In *First Conference on Language Modeling*, 2024. URL https://openreview.net/forum?id=3X2L2TFr0f.

Hamel Husain, Ho-Hsiang Wu, Tiferet Gazit, Miltiadis Allamanis, and Marc Brockschmidt. Codesearchnet challenge: Evaluating the state of semantic code search. *arXiv preprint arXiv:1909.09436*, 2019. URL https://arxiv.org/abs/1909.09436.
Mingi Jeon, Seung-yeop Baik, Joonghyuk Hahn, Yo-Sub Han, and Sang-Ki Ko. Deep learning-based source code complexity prediction. 2023. URL https://openreview.net/forum?id=9irBKvxsw9.

Vladimir Karpukhin, Barlas Oguz, Sewon Min, Patrick Lewis, Ledell Wu, Sergey Edunov, Danqi Chen, and Wen-tau Yih. Dense passage retrieval for open-domain question answering. In *Proceedings of the 2020 Conference on Empirical Methods in Natural Language Processing (EMNLP)*, Online, November 2020. Association for Computational Linguistics. URL https://aclanthology.org/2020.emnlp-main.550/.

Phillip Keung, Yichao Lu, György Szarvas, and Noah A. Smith. The multilingual Amazon reviews corpus. In *Proceedings of the 2020 Conference on Empirical Methods in Natural Language Processing (EMNLP)*, Online, November 2020. Association for Computational Linguistics. URL https://aclanthology.org/2020.emnlp-main.369/.

Tom Kocmi, Rachel Bawden, Ondřej Bojar, Anton Dvorkovich, Christian Federmann, Mark Fishel, Thamme Gowda, Yvette Graham, Roman Grundkiewicz, Barry Haddow, Rebecca Knowles, Philipp Koehn, Christof Monz, Makoto Morishita, Masaaki Nagata, Toshiaki Nakazawa, Michal Novák, Martin Popel, and Maja Popović. Findings of the 2022 conference on machine translation (WMT22). In *Proceedings of the Seventh Conference on Machine Translation (WMT)*, Abu Dhabi, United Arab Emirates (Hybrid), December 2022. Association for Computational Linguistics. URL https://aclanthology.org/2022.wmt-1.1/.

Yaobo Liang, Nan Duan, Yeyun Gong, Ning Wu, Fenfei Guo, Weizhen Qi, Ming Gong, Linjun Shou, Daxin Jiang, Guihong Cao, Xiaodong Fan, Ruofei Zhang, Rahul Agrawal, Edward Cui, Sining Wei, Taroon Bharti, Ying Qiao, Jiun-Hung Chen, Winnie Wu, Shuguang Liu, Fan Yang, Daniel Campos, Rangan Majumder, and Ming Zhou. XGLUE: A new benchmark dataset for cross-lingual pre-training, understanding and generation. In *Proceedings of the 2020 Conference on Empirical Methods in Natural Language Processing (EMNLP)*, Online, November 2020. Association for Computational Linguistics. URL https://aclanthology.org/2020.emnlp-main.484/.

Yinhan Liu, Myle Ott, Naman Goyal, Jingfei Du, Mandar Joshi, Danqi Chen, Omer Levy, Mike Lewis, Luke Zettlemoyer, and Veselin Stoyanov. Roberta: A robustly optimized bert pretraining approach, 2019. URL https://arxiv.org/abs/1907.11692.

AI @ Meta Llama Team. The llama 3 herd of models, 2024. URL https://arxiv.org/abs/2407.21783.

Anton Lozhkov, Raymond Li, Loubna Ben Allal, Federico Cassano, Joel Lamy-Poirier, Nouamane Tazi, Ao Tang, Dmytro Pykhtar, Jiawei Liu, Yuxiang Wei, et al. Starcoder 2 and the stack v2: The next generation. *arXiv preprint arXiv:2402.19173*, 2024. URL https://arxiv.org/abs/2402.19173.

Xiaofei Ma, Peng Xu, Zhiguo Wang, Ramesh Nallapati, and Bing Xiang. Domain adaptation with BERT-based domain classification and data selection. In *Proceedings of the 2nd Workshop on Deep Learning Approaches for Low-Resource NLP (DeepLo 2019)*, Hong Kong, China, November 2019. Association for Computational Linguistics. URL https://aclanthology.org/D19-6109/.

Pedro Henrique Martins, Patrick Fernandes, João Alves, Nuno M. Guerreiro, Ricardo Rei, Duarte M. Alves, José Pombal, Amin Farajian, Manuel Faysse, Mateusz Klimaszewski, Pierre Colombo, Barry Haddow, José G. C. de Souza, Alexandra Birch, and André F. T. Martins. Eurollm: Multilingual language models for europe, 2024. URL https://arxiv.org/abs/2409.16235.

Thuat Nguyen, Chien Van Nguyen, Viet Dac Lai, Hieu Man, Nghia Trung Ngo, Franck Dernoncourt, Ryan A. Rossi, and Thien Huu Nguyen. CulturaX: A cleaned, enormous, and multilingual dataset for large language models in 167 languages. In *Proceedings of the 2024 Joint International Conference on Computational Linguistics, Language Resources and Evaluation (LREC-COLING 2024)*, Torino, Italia, May 2024. ELRA and ICCL. URL https://aclanthology.org/2024.lrec-main.377/.
Team OLMo, Pete Walsh, Luca Soldaini, Dirk Groeneveld, Kyle Lo, Shane Arora, Akshita Bhagia, Yuling Gu, Shengyi Huang, Matt Jordan, Nathan Lambert, Dustin Schwenk, Oyvind Tafjord, Taira Anderson, David Atkinson, Faeze Brahman, Christopher Clark, Pradeep Dasigi, Nouha Dziri, Michal Guerquin, Hamish Ivison, Pang Wei Koh, Jiacheng Liu, Saumya Malik, William Merrill, Lester James V. Miranda, Jacob Morrison, Tyler Murray, Crystal Nam, Valentina Pyatkin, Aman Rangapur, Michael Schmitz, Sam Skjonsberg, David Wadden, Christopher Wilhelm, Michael Wilson, Luke Zettlemoyer, Ali Farhadi, Noah A. Smith, and Hannaneh Hajishirzi. 2 olmo 2 furious, 2025. URL https://arxiv.org/abs/2501.00656.

Aaron van den Oord, Yazhe Li, and Oriol Vinyals. Representation learning with contrastive predictive coding. arXiv preprint arXiv:1807.03748, 2018. URL https://arxiv.org/abs/1807.03748.

Guilherme Penedo, Hynek Kydlíček, Loubna Ben allal, Anton Lozhkov, Margaret Mitchell, Colin A Raffel, Leandro Von Werra, and Thomas Wolf. The fineweb datasets: Decanting the web for the finest text data at scale. In Advances in Neural Information Processing Systems, volume 37. Curran Associates, Inc., 2024. URL https://proceedings.neurips.cc/paper_files/paper/2024/file/370df50ccfdf8bde18f8f9c2d9151bda-Paper-Datasets_and_Benchmarks_Track.pdf.

Machel Reid and Mikel Artetxe. PARADISE: Exploiting parallel data for multilingual sequence-to-sequence pretraining. In Proceedings of the 2022 Conference of the North American Chapter of the Association for Computational Linguistics: Human Language Technologies, Seattle, United States, July 2022. Association for Computational Linguistics. URL https://aclanthology.org/2022.naacl-main.58/.

Machel Reid and Mikel Artetxe. On the role of parallel data in cross-lingual transfer learning. In Findings of the Association for Computational Linguistics: ACL 2023, Toronto, Canada, July 2023. Association for Computational Linguistics. URL https://aclanthology.org/2023.findings-acl.372/.

Noam Shazeer. Glu variants improve transformer, 2020. URL https://arxiv.org/abs/2002.05202.

Yikang Shen, Matthew Stallone, Mayank Mishra, Gaoyuan Zhang, Shawn Tan, Aditya Prasad, Adriana Meza Soria, David D. Cox, and Rameswar Panda. Power scheduler: A batch size and token number agnostic learning rate scheduler, 2024. URL https://arxiv.org/abs/2408.13359.

Jianlin Su, Murtadha Ahmed, Yu Lu, Shengfeng Pan, Wen Bo, and Yunfeng Liu. Roformer: Enhanced transformer with rotary position embedding. Neurocomputing, 568, 2024. ISSN 0925-2312. URL https://www.sciencedirect.com/science/article/pii/S0925231223011864.

Erik F. Tjong Kim Sang. Introduction to the CoNLL-2002 shared task: Language-independent named entity recognition. In COLING-02: The 6th Conference on Natural Language Learning 2002 (CoNLL-2002), 2002. URL https://www.aclweb.org/anthology/W02-2024.

Erik F. Tjong Kim Sang and Fien De Meulder. Introduction to the CoNLL-2003 shared task: Language-independent named entity recognition. In Proceedings of the Seventh Conference on Natural Language Learning at HLT-NAACL 2003, pp. 142–147, 2003. URL https://www.aclweb.org/anthology/W03-0419.

Hugo Touvron, Louis Martin, Kevin Stone, Peter Albert, Amjad Almahairi, Yasmine Babaei, Nikolay Bashlykov, Soumya Batra, Prajjwal Bhargava, Shruti Bhosale, Dan Bikel, Lukas Blecher, Cristian Canton Ferrer, Moya Chen, Guillem Cucurull, David Esiobu, Jude Fernandes, Jeremy Fu, Wenyin Fu, Brian Fuller, Cynthia Gao, Vedanuj Goswami, Naman Goyal, Anthony Hartshorn, Saghar Hosseini, Rui Hou, Hakan Inan, Marcin Kardas, Viktor Kerkez, Madian Khabsa, Isabel Kloumann, Artem Korenev, Punit Singh Koura, Marie-Anne Lachaux, Thibaut Lavril, Jenya Lee, Diana Liskovich, Yinghai Lu, Yuning Mao, Xavier Martinet, Todor Mihaylov, Pushkar Mishra, Igor Molybog, Yixin Nie, Andrew
Poulton, Jeremy Reizenstein, Rashi Rungta, Kalyan Saladi, Alan Schelten, Ruan Silva, Eric Michael Smith, Ranjan Subramanian, Xiaoqing Ellen Tan, Binh Tang, Ross Taylor, Adina Williams, Jian Xiang Kuan, Puxin Xu, Zheng Yan, Iliyan Zarov, Yuchen Zhang, Angela Fan, Melanie Kambadur, Sharan Narang, Aurelien Rodriguez, Robert Stojnic, Sergey Edunov, and Thomas Scialom. Llama 2: Open foundation and fine-tuned chat models, 2023. URL https://arxiv.org/abs/2307.09288.

Ashish Vaswani, Noam Shazeer, Niki Parmar, Jakob Uszkoreit, Llion Jones, Aidan N Gomez, Łukasz Kaiser, and Illia Polosukhin. Attention is all you need. In *Advances in Neural Information Processing Systems*, 2017. URL https://proceedings.neurips.cc/paper_files/paper/2017/file/3f5ee243547dee91fbd053c1c4a845aa-Paper.pdf.

Liang Wang, Nan Yang, Xiaolong Huang, Binxing Jiao, Linjun Yang, Daxin Jiang, Rangan Majumder, and Furu Wei. Text embeddings by weakly-supervised contrastive pre-training, 2024a. URL https://arxiv.org/abs/2212.03533.

Peiyi Wang, Lei Li, Zhihong Shao, Runxin Xu, Damai Dai, Yifei Li, Deli Chen, Yu Wu, and Zhifang Sui. Math-shepherd: Verify and reinforce LLMs step-by-step without human annotations. In *Proceedings of the 62nd Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers)*, Bangkok, Thailand, August 2024b. Association for Computational Linguistics. URL https://aclanthology.org/2024.acl-long.510/.

Benjamin Warner, Antoine Chaffin, Benjamin Clavié, Orion Weller, Oskar Hallström, Said Taghadouini, Alexis Gallagher, Raja Biswas, Faisal Ladhak, Tom Aarsen, Nathan Cooper, Griffin Adams, Jeremy Howard, and Iacopo Poli. Smarter, better, faster, longer: A modern bidirectional encoder for fast, memory efficient, and long context finetuning and inference, 2024. URL https://arxiv.org/abs/2412.13663.

Jason Wei, Maarten Bosma, Vincent Zhao, Kelvin Guu, Adams Wei Yu, Brian Lester, Nan Du, Andrew M. Dai, and Quoc V Le. Finetuned language models are zero-shot learners. In *International Conference on Learning Representations*, 2022. URL https://openreview.net/forum?id=gEZrGCozdqR.

Alexander Wettig, Tianyu Gao, Zexuan Zhong, and Danqi Chen. Should you mask 15% in masked language modeling? In *Proceedings of the 17th Conference of the European Chapter of the Association for Computational Linguistics*, Dubrovnik, Croatia, May 2023. Association for Computational Linguistics. URL https://aclanthology.org/2023.eacl-main.217/.

Adina Williams, Nikita Nangia, and Samuel Bowman. A broad-coverage challenge corpus for sentence understanding through inference. In *Proceedings of the 2018 Conference of the North American Chapter of the Association for Computational Linguistics: Human Language Technologies, Volume 1 (Long Papers)*, New Orleans, Louisiana, June 2018. Association for Computational Linguistics. URL https://aclanthology.org/N18-1101/.

An Yang, Baosong Yang, Binyuan Hui, Bo Zheng, Bowen Yu, Chang Zhou, Chengpeng Li, Chengyuan Li, Dayiheng Liu, Fei Huang, Guanting Dong, Haoran Wei, Huan Lin, Jialong Tang, Jialin Wang, Jian Yang, Jianhong Tu, Jianwei Zhang, Jianxin Ma, Jianxin Yang, Jin Xu, Jingren Zhou, Jinze Bai, Jinzheng He, Junyang Lin, Kai Dang, Keming Lu, Keqin Chen, Kexin Yang, Mei Li, Mingfeng Xue, Na Ni, Pei Zhang, Peng Wang, Ru Peng, Rui Men, Ruize Gao, Runji Lin, Shijie Wang, Shuai Bai, Sinan Tan, Tianhang Zhu, Tianhao Li, Tianyu Liu, Wenbin Ge, Xiaodong Deng, Xiaohuan Zhou, Xingzhang Ren, Xinyu Zhang, Xipin Wei, Xuancheng Ren, Xuejing Liu, Yang Fan, Yang Yao, Yichang Zhang, Yu Wan, Yunfei Chu, Yuqiong Liu, Zeyu Cui, Zhenru Zhang, Zhifang Guo, and Zhihao Fan. Qwen2 technical report, 2024. URL https://arxiv.org/abs/2407.10671.

Dongjie Yang, Zhuosheng Zhang, and Hai Zhao. Learning better masking for better language model pre-training. In *Proceedings of the 61st Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers)*, Toronto, Canada, July 2023. Association for Computational Linguistics. URL https://aclanthology.org/2023.acl-long.400/.

Yinfei Yang, Yuan Zhang, Chris Tar, and Jason Baldridge. PAWS-X: A cross-lingual adversarial dataset for paraphrase identification. In *Proceedings of the 2019 Conference on Empirical*
*Methods in Natural Language Processing and the 9th International Joint Conference on Natural Language Processing (EMNLP-IJCNLP)*, Hong Kong, China, November 2019. Association for Computational Linguistics. URL https://aclanthology.org/D19-1382/.

Biao Zhang and Rico Sennrich. Root mean square layer normalization. In *Advances in Neural Information Processing Systems*, volume 32. Curran Associates, Inc., 2019. URL https://proceedings.neurips.cc/paper_files/paper/2019/file/1e8a19426224ca89e83cef47f1e7f53b-Paper.pdf.

Xin Zhang, Yanzhao Zhang, Dingkun Long, Wen Xie, Ziqi Dai, Jialong Tang, Huan Lin, Baosong Yang, Pengjun Xie, Fei Huang, Meishan Zhang, Wenjie Li, and Min Zhang. mGTE: Generalized long-context text representation and reranking models for multilingual text retrieval. In *Proceedings of the 2024 Conference on Empirical Methods in Natural Language Processing: Industry Track*, Miami, Florida, US, November 2024. Association for Computational Linguistics. URL https://aclanthology.org/2024.emnlp-industry.103/.

Xinyu Zhang, Nandan Thakur, Odunayo Ogundepo, Ehsan Kamalloo, David Alfonso-Hermelo, Xiaoguang Li, Qun Liu, Mehdi Rezagholizadeh, and Jimmy Lin. MIRACL: A multilingual retrieval dataset covering 18 diverse languages. *Transactions of the Association for Computational Linguistics*, 11, 2023. URL https://aclanthology.org/2023.tacl-1.63/.

Yanli Zhao, Andrew Gu, Rohan Varma, Liang Luo, Chien-Chin Huang, Min Xu, Less Wright, Hamid Shojanazeri, Myle Ott, Sam Shleifer, et al. Pytorch fsdp: Experiences on scaling fully sharded data parallel. *Proceedings of the VLDB Endowment*, 16(12), 2023. URL https://dl.acm.org/doi/abs/10.14778/3611540.3611569.

Yaqin Zhou, Shangqing Liu, Jingkai Siow, Xiaoning Du, and Yang Liu. Devign: Effective vulnerability identification by learning comprehensive program semantics via graph neural networks. In *Advances in Neural Information Processing Systems*, volume 32. Curran Associates, Inc., 2019. URL https://proceedings.neurips.cc/paper_files/paper/2019/file/49265d2447bc3bbfe9e76306ce40a31f-Paper.pdf.
## A EuroBERT Model Architecture

Table 3 reports the architectural details of the EuroBERT model family.

<table><caption>Table 3: Summary of architectural hyperparameters for EuroBERT models of different sizes.</caption><thead><tr><th>Model Size</th><th>210M</th><th>610M</th><th>2.1B</th></tr></thead><tbody><tr><td>Layers</td><td>12</td><td>26</td><td>32</td></tr><tr><td>Embedding Dimension</td><td>768</td><td>1,152</td><td>2,304</td></tr><tr><td>FFN Dimension</td><td>3,072</td><td>4,096</td><td>6,144</td></tr><tr><td>Attention Heads</td><td>12</td><td>18</td><td>18</td></tr><tr><td>Key/Value Heads</td><td>12</td><td>6</td><td>6</td></tr><tr><td>Layer Normalization</td><td colspan="3">RMSNorm</td></tr><tr><td>RMSNorm ε</td><td colspan="3">1 × 10<sup>-5</sup></td></tr><tr><td>Activation Function</td><td colspan="3">SwiGLU</td></tr><tr><td>Vocabulary Size</td><td colspan="3">128,000</td></tr><tr><td>Positional Embeddings</td><td colspan="3">RoPE</td></tr><tr><td>RoPE θ</td><td colspan="3">250,000</td></tr><tr><td>Tokenizer</td><td colspan="3">LLaMA 3</td></tr></tbody></table>

## B Training Details

We trained the EuroBERT family on Adastra, utilizing 92 MI250X GPUs for EuroBERT-210M over 15k hours, 384 MI250X GPUs for EuroBERT-610M over 92k hours, and 96 MI300A GPUs for EuroBERT-2.1B over 106k hours, hyperparameter selections are detailed in Table 4. We find this training recipe highly stable, with no loss spikes or need for intervention to address model training divergence (Figure 7).

<figure><img src="image_11.png" /><figcaption>Figure 7: Pre-training Loss for all EuroBERT models on a logarithmic scale.</figcaption></figure>
<table><caption>Table 4: Training hyperparameters for EuroBERT models (210M, 610M, 2.1B). The optimizer and Tokens/Step remain consistent across both pre-training and annealing phases.</caption><thead><tr><th>Parameter</th><th>210M</th><th>610M</th><th>2.1B</th></tr></thead><tbody><tr><td colspan="4"><strong>Pre-training</strong></td></tr><tr><td>LR</td><td></td><td>1e-4</td><td></td></tr><tr><td>LR Scheduler</td><td></td><td>WSD</td><td></td></tr><tr><td>Warmup Steps</td><td></td><td>2,000</td><td></td></tr><tr><td>Context Length</td><td></td><td>2,048</td><td></td></tr><tr><td>Weight Initialisation</td><td></td><td>N(μ = 0, σ² = 0.2)</td><td></td></tr><tr><td colspan="4"><strong>Annealing</strong></td></tr><tr><td>LR</td><td></td><td>1e-4 to 0</td><td></td></tr><tr><td>LR Scheduler</td><td></td><td>Cosine</td><td></td></tr><tr><td>Context Length</td><td></td><td>8,192</td><td></td></tr><tr><td colspan="4"><strong>Optimizer</strong></td></tr><tr><td>Optimizer</td><td></td><td>AdamW</td><td></td></tr><tr><td>Beta1</td><td></td><td>0.9</td><td></td></tr><tr><td>Beta2</td><td></td><td>0.95</td><td></td></tr><tr><td>Epsilon (eps)</td><td></td><td>1e-5</td><td></td></tr><tr><td>Weight Decay</td><td></td><td>0.1</td><td></td></tr><tr><td>Clip Grad Norm</td><td></td><td>1.0</td><td></td></tr><tr><td colspan="4"><strong>Training Setup</strong></td></tr><tr><td>Per-GPU Batch Size</td><td>24</td><td>12</td><td>10</td></tr><tr><td>Gradient Accumulation Steps</td><td>1</td><td>1</td><td>5</td></tr><tr><td>GPUs</td><td>192</td><td>384</td><td>96</td></tr><tr><td>Tokens/Step</td><td>9,437,184</td><td>9,437,184</td><td>9,830,400</td></tr></tbody></table>
## C Data Mix

Table 5 details the data sources used throughout training, as well as the number of tokens used from each of the data source during pre-training. Table 6 specifies the different annealing mixes used for ablations.

<table><thead><tr><th>Source</th><th>Subset</th><th>Tokens (M)</th><th>Mix (%)</th><th>Source</th><th>Subset</th><th>Tokens (M)</th><th>Mix (%)</th></tr></thead><tbody><tr><td>FineWeb</td><td>English</td><td>2,002,327</td><td>41.34</td><td>The-Stack v2</td><td>JavaScript</td><td>58,440</td><td>1.21</td></tr><tr><td>CulturaX</td><td>French</td><td>295,113</td><td>6.09</td><td>The-Stack v2</td><td>PHP</td><td>25,620</td><td>0.53</td></tr><tr><td>CulturaX</td><td>German</td><td>291,514</td><td>6.02</td><td>The-Stack v2</td><td>C#</td><td>24,842</td><td>0.51</td></tr><tr><td>CulturaX</td><td>Spanish</td><td>290,489</td><td>6.00</td><td>The-Stack v2</td><td>Python</td><td>21,521</td><td>0.44</td></tr><tr><td>CulturaX</td><td>Chinese</td><td>238,467</td><td>4.92</td><td>The-Stack v2</td><td>Java</td><td>20,950</td><td>0.43</td></tr><tr><td>CulturaX</td><td>Italian</td><td>120,128</td><td>2.48</td><td>The-Stack v2</td><td>Go</td><td>14,766</td><td>0.30</td></tr><tr><td>CulturaX</td><td>Russian</td><td>116,797</td><td>2.41</td><td>The-Stack v2</td><td>TypeScript</td><td>11,307</td><td>0.23</td></tr><tr><td>CulturaX</td><td>Portuguese</td><td>112,321</td><td>2.32</td><td>The-Stack v2</td><td>HTML</td><td>7,962</td><td>0.16</td></tr><tr><td>CulturaX</td><td>Japanese</td><td>112,242</td><td>2.32</td><td>The-Stack v2</td><td>Lua</td><td>7,733</td><td>0.16</td></tr><tr><td>CulturaX</td><td>Polish</td><td>111,659</td><td>2.31</td><td>The-Stack v2</td><td>Ruby</td><td>5,524</td><td>0.11</td></tr><tr><td>CulturaX</td><td>Turkish</td><td>53,126</td><td>1.10</td><td>The-Stack v2</td><td>Vue</td><td>5,411</td><td>0.11</td></tr><tr><td>CulturaX</td><td>Arabic</td><td>52,413</td><td>1.08</td><td>The-Stack v2</td><td>R</td><td>5,287</td><td>0.11</td></tr><tr><td>CulturaX</td><td>Vietnamese</td><td>50,661</td><td>1.05</td><td>The-Stack v2</td><td>Shell</td><td>4,793</td><td>0.10</td></tr><tr><td>CulturaX</td><td>Dutch</td><td>50,646</td><td>1.05</td><td>The-Stack v2</td><td>Swift</td><td>3,766</td><td>0.08</td></tr><tr><td>CulturaX</td><td>Hindi</td><td>25,544</td><td>0.53</td><td>The-Stack v2</td><td>reStructuredText</td><td>3,761</td><td>0.08</td></tr><tr><td>EuroLLM Parallel</td><td>es ↔ en</td><td>50,613</td><td>1.05</td><td>The-Stack v2</td><td>JSON</td><td>3,586</td><td>0.07</td></tr><tr><td>EuroLLM Parallel</td><td>fr ↔ en</td><td>44,891</td><td>0.93</td><td>The-Stack v2</td><td>Rust</td><td>3,152</td><td>0.07</td></tr><tr><td>EuroLLM Parallel</td><td>de ↔ en</td><td>30,541</td><td>0.63</td><td>The-Stack v2</td><td>YAML</td><td>2,716</td><td>0.06</td></tr><tr><td>EuroLLM Parallel</td><td>it ↔ en</td><td>18,702</td><td>0.39</td><td>The-Stack v2</td><td>Dart</td><td>2,678</td><td>0.06</td></tr><tr><td>EuroLLM Parallel</td><td>ru ↔ en</td><td>13,808</td><td>0.29</td><td>The-Stack v2</td><td>RMarkdown</td><td>2,058</td><td>0.04</td></tr><tr><td>EuroLLM Parallel</td><td>nl ↔ en</td><td>12,666</td><td>0.26</td><td>The-Stack v2</td><td>HCL</td><td>1,423</td><td>0.03</td></tr><tr><td>EuroLLM Parallel</td><td>pl ↔ en</td><td>7,280</td><td>0.15</td><td>The-Stack v2</td><td>PowerShell</td><td>1,027</td><td>0.02</td></tr><tr><td>EuroLLM Parallel</td><td>ar ↔ en</td><td>6,414</td><td>0.13</td><td>The-Stack v2</td><td>VBA</td><td>1,027</td><td>0.02</td></tr><tr><td>EuroLLM Parallel</td><td>zh ↔ en</td><td>6,206</td><td>0.13</td><td>The-Stack v2</td><td>InternDoc</td><td>970</td><td>0.02</td></tr><tr><td>EuroLLM Parallel</td><td>cs ↔ en</td><td>5,458</td><td>0.11</td><td>The-Stack v2</td><td>Groovy</td><td>540</td><td>0.01</td></tr><tr><td>EuroLLM Parallel</td><td>hu ↔ en</td><td>4,599</td><td>0.09</td><td>The-Stack v2</td><td>CUDA</td><td>406</td><td>0.01</td></tr><tr><td>EuroLLM Parallel</td><td>vi ↔ en</td><td>3,395</td><td>0.07</td><td>The-Stack v2</td><td>Dockerfile</td><td>281</td><td>0.01</td></tr><tr><td>EuroLLM Parallel</td><td>tr ↔ en</td><td>2,975</td><td>0.06</td><td>The-Stack v2</td><td>Cython</td><td>103</td><td>0.01</td></tr><tr><td>EuroLLM Parallel</td><td>ja ↔ en</td><td>2,687</td><td>0.06</td><td>The-Stack v2</td><td>COBOL</td><td>96</td><td>0.01</td></tr><tr><td>EuroLLM Parallel</td><td>hi ↔ en</td><td>1,136</td><td>0.02</td><td>The-Stack v2</td><td>GraphQL</td><td>83</td><td>0.01</td></tr><tr><td>Proof-pile-2</td><td>Arxiv</td><td>121,503</td><td>2.51</td><td>The-Stack v2</td><td>HTTP</td><td>82</td><td>0.01</td></tr><tr><td>Proof-pile-2</td><td>Open-Web-Math</td><td>54,168</td><td>1.12</td><td>The-Stack v2</td><td>ABAP</td><td>71</td><td>0.01</td></tr><tr><td>Proof-pile-2</td><td>Algebraic-stack</td><td>35,985</td><td>0.74</td><td>The-Stack v2</td><td>RDoc</td><td>16</td><td>0.01</td></tr><tr><td>The-Stack v2</td><td>C++</td><td>120,085</td><td>2.48</td><td>The-Stack v2</td><td>Metal</td><td>8</td><td>0.01</td></tr><tr><td>The-Stack v2</td><td>SQL</td><td>75,348</td><td>1.56</td><td>The-Stack v2</td><td>AppleScript</td><td>7</td><td>0.01</td></tr><tr><td>The-Stack v2</td><td>C</td><td>59,404</td><td>1.23</td><td>Total</td><td></td><td>4,843,357</td><td>100</td></tr></tbody></table>

Table 5: Pre-training data, with a total of 4.8 trillion tokens (as measured by EuroBERT's tokenizer). We report the list of all dataset names and subsets used, including the number of tokens selected and their proportion in the final data mix.

<table><thead><tr><th>Mix</th><th>en</th><th>fr</th><th>de</th><th>nl</th><th>hi</th><th>it</th><th>ja</th><th>pl</th><th>pt</th><th>ru</th><th>es</th><th>ar</th><th>zh</th><th>tr</th><th>Code</th><th>Math</th><th>Parallel</th><th>IFT</th></tr></thead><tbody><tr><td>Reference</td><td>46.3</td><td>5.8</td><td>5.7</td><td>1.0</td><td>0.3</td><td>1.5</td><td>0.8</td><td>1.0</td><td>1.4</td><td>1.0</td><td>5.7</td><td>0.4</td><td>4.7</td><td>1.0</td><td>8.7</td><td>8.2</td><td>5.2</td><td>1.2</td></tr><tr><td>English 26%</td><td>26.0</td><td>6.0</td><td>6.0</td><td>4.0</td><td>4.0</td><td>4.0</td><td>4.0</td><td>4.0</td><td>4.0</td><td>4.0</td><td>6.0</td><td>4.0</td><td>6.0</td><td>4.0</td><td>4.0</td><td>4.0</td><td>5.0</td><td>1.0</td></tr><tr><td>English 17%</td><td>17.0</td><td>6.0</td><td>6.0</td><td>5.0</td><td>5.0</td><td>5.0</td><td>5.0</td><td>5.0</td><td>5.0</td><td>5.0</td><td>6.0</td><td>5.0</td><td>6.0</td><td>5.0</td><td>4.0</td><td>4.0</td><td>5.0</td><td>1.0</td></tr><tr><td>Math 4%</td><td>46.3</td><td>5.8</td><td>5.7</td><td>1.0</td><td>0.3</td><td>1.5</td><td>0.8</td><td>1.0</td><td>1.4</td><td>1.0</td><td>5.7</td><td>0.4</td><td>4.7</td><td>1.0</td><td>8.7</td><td>4.0</td><td>5.2</td><td>1.2</td></tr><tr><td>Math 2%</td><td>46.3</td><td>5.8</td><td>5.7</td><td>1.0</td><td>0.3</td><td>1.5</td><td>0.8</td><td>1.0</td><td>1.4</td><td>1.0</td><td>5.7</td><td>0.4</td><td>4.7</td><td>1.0</td><td>8.7</td><td>2.0</td><td>5.2</td><td>1.2</td></tr><tr><td>Code 8%</td><td>46.3</td><td>5.8</td><td>5.7</td><td>1.0</td><td>0.3</td><td>1.5</td><td>0.8</td><td>1.0</td><td>1.4</td><td>1.0</td><td>5.7</td><td>0.4</td><td>4.7</td><td>1.0</td><td>6.0</td><td>8.2</td><td>5.2</td><td>1.2</td></tr><tr><td>Code 4%</td><td>46.3</td><td>5.8</td><td>5.7</td><td>1.0</td><td>0.3</td><td>1.5</td><td>0.8</td><td>1.0</td><td>1.4</td><td>1.0</td><td>5.7</td><td>0.4</td><td>4.7</td><td>1.0</td><td>4.0</td><td>8.2</td><td>5.2</td><td>1.2</td></tr><tr><td>Code 2%</td><td>46.3</td><td>5.8</td><td>5.7</td><td>1.0</td><td>0.3</td><td>1.5</td><td>0.8</td><td>1.0</td><td>1.4</td><td>1.0</td><td>5.7</td><td>0.4</td><td>4.7</td><td>1.0</td><td>2.0</td><td>8.2</td><td>5.2</td><td>1.2</td></tr><tr><td>Parallel 8%</td><td>46.3</td><td>5.8</td><td>5.7</td><td>1.0</td><td>0.3</td><td>1.5</td><td>0.8</td><td>1.0</td><td>1.4</td><td>1.0</td><td>5.7</td><td>0.4</td><td>4.7</td><td>1.0</td><td>8.7</td><td>8.2</td><td>8.0</td><td>1.2</td></tr><tr><td>IFT 0%</td><td>46.3</td><td>5.8</td><td>5.7</td><td>1.0</td><td>0.3</td><td>1.5</td><td>0.8</td><td>1.0</td><td>1.4</td><td>1.0</td><td>5.7</td><td>0.4</td><td>4.7</td><td>1.0</td><td>8.7</td><td>8.2</td><td>5.2</td><td>0.0</td></tr></tbody></table>

Table 6: Data mix employed in the ablation study measuring the importance of different data subsets in the EuroBERT annealing phase.
## D Details of Evaluation Datasets

This appendix offers additional details on the datasets used for evaluation. Table 7 presents the language coverage of all evaluation datasets, and below are additional specifications on the evaluated tasks.

<table><caption>Table 7: Language coverage across evaluation datasets.</caption><thead><tr><th rowspan="2">Task</th><th colspan="8">European Languages</th><th colspan="8">Extra-European Languages</th><th rowspan="2">Code</th><th rowspan="2">Math</th></tr><tr><th>en</th><th>de</th><th>es</th><th>fr</th><th>it</th><th>nl</th><th>pl</th><th>pt</th><th>ar</th><th>hi</th><th>ja</th><th>ru</th><th>tr</th><th>vi</th><th>zh</th></tr></thead><tbody><tr><td colspan="18" style="text-align:center; font-weight:bold;">Information Retrieval</td></tr><tr><td>MIRACL</td><td>✓</td><td></td><td>✓</td><td>✓</td><td></td><td></td><td></td><td></td><td></td><td>✓</td><td>✓</td><td>✓</td><td>✓</td><td></td><td></td><td>✓</td></tr><tr><td>MLDR</td><td>✓</td><td>✓</td><td>✓</td><td>✓</td><td>✓</td><td></td><td></td><td></td><td>✓</td><td>✓</td><td>✓</td><td>✓</td><td></td><td></td><td></td><td>✓</td></tr><tr><td>Wikipedia</td><td>✓</td><td>✓</td><td>✓</td><td>✓</td><td>✓</td><td>✓</td><td></td><td></td><td>✓</td><td></td><td></td><td>✓</td><td></td><td></td><td></td><td></td></tr><tr><td>CC-News</td><td>✓</td><td>✓</td><td>✓</td><td>✓</td><td>✓</td><td>✓</td><td>✓</td><td>✓</td><td>✓</td><td>✓</td><td>✓</td><td>✓</td><td>✓</td><td>✓</td><td>✓</td><td></td></tr><tr><td>CodeSearchNet</td><td>✓</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td>✓</td></tr><tr><td>DupStackMath</td><td>✓</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td>✓</td></tr><tr><td>MathFormula</td><td>✓</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td>✓</td></tr><tr><td colspan="18" style="text-align:center; font-weight:bold;">Sequence Classification</td></tr><tr><td>XNLI</td><td>✓</td><td>✓</td><td>✓</td><td>✓</td><td></td><td></td><td></td><td></td><td>✓</td><td>✓</td><td></td><td>✓</td><td>✓</td><td>✓</td><td>✓</td><td></td></tr><tr><td>PAWS-X</td><td>✓</td><td>✓</td><td>✓</td><td>✓</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>AmazonReviews</td><td>✓</td><td>✓</td><td>✓</td><td>✓</td><td></td><td></td><td></td><td></td><td></td><td></td><td>✓</td><td></td><td>✓</td><td>✓</td><td>✓</td><td></td></tr><tr><td>MassiveIntent</td><td>✓</td><td>✓</td><td>✓</td><td>✓</td><td>✓</td><td>✓</td><td>✓</td><td>✓</td><td>✓</td><td>✓</td><td>✓</td><td>✓</td><td>✓</td><td>✓</td><td>✓</td><td></td></tr><tr><td>CodeDefect</td><td>✓</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td>✓</td></tr><tr><td>CodeComplexity</td><td>✓</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td>✓</td></tr><tr><td>MathShepherd</td><td>✓</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td>✓</td></tr><tr><td colspan="18" style="text-align:center; font-weight:bold;">Sequence Regression</td></tr><tr><td>WMT</td><td>✓</td><td>✓</td><td>✓</td><td>✓</td><td></td><td></td><td></td><td></td><td>✓</td><td>✓</td><td>✓</td><td>✓</td><td>✓</td><td></td><td></td><td></td></tr><tr><td>SeaHorse</td><td>✓</td><td>✓</td><td>✓</td><td>✓</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td>✓</td><td>✓</td><td></td><td></td><td></td></tr><tr><td colspan="18" style="text-align:center; font-weight:bold;">Token Classification</td></tr><tr><td>NER</td><td>✓</td><td>✓</td><td>✓</td><td>✓</td><td></td><td></td><td></td><td></td><td>✓</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td></tr></tbody></table>

### Retrieval datasets:

* **MS-MARCO** (Bajaj et al., 2016) — English-only retrieval dataset used for fine-tuning, where each anchor-positive pair includes a mined hard negative, forming a triplet structure.

* **MIRACL** (Zhang et al., 2023) — Multilingual retrieval dataset. We use the semi-supervised version with labeled positive pairs provided by SentenceTransformers<fnref n="16" /> as the primary data source. Anchors serve as queries, and the corpus consists of all positive documents in the dataset. Since only a single data split is available, we create validation and test sets by partitioning 50% of the original split for each, using queries as the split key to ensure no data leakage.

* **MLDR** (Chen et al., 2024) — Long-context multilingual retrieval dataset. As with MIRACL, we use the triplet version provided by SentenceTransformers and apply the same validation-test split strategy.

* **Wikipedia**<fnref n="17" /> — Multilingual information retrieval dataset. Since only a single data split is available, we partition 50% of the queries into validation and test sets.

* **CC-News** (de Gibert et al., 2024) — Highly multilingual retrieval dataset. As with MIRACL, we use the SentenceTransformers dataset version as the primary data source and apply the same test-validation split method.

* **CodeSearchNet** (Husain et al., 2019) — Code retrieval dataset with comment-code query-positive pairs (SentenceTransformers version), processed similarly to the previous datasets.

<footnote n="16">¹⁶https://huggingface.co/collections/sentence-transformers/embedding-model-datasets-6644d7a3673a511914aa7552</footnote>

<footnote n="17">¹⁷https://huggingface.co/datasets/Samoed/WikipediaRetrievalMultilingual</footnote>
* DupStackMath (Hoogeveen et al., 2015) — Code retrieval dataset with queries, a corpus, and relevant documents, processed the same way as the above datasets.

* MathFormula (Drechsel et al., 2025) — Mathematical retrieval dataset consisting of pairs of equivalent formulas. The original dataset contains formula pairs labeled as true or false based on their equivalence, spanning 71 well-known mathematical formulas. To construct the retrieval dataset, we extract only equivalent formula pairs, retaining positive instances. Due to the dataset's large size, we sample 100 positive pairs per formula type for both validation and test sets. The final dataset is processed following the same methodology as other pair-based datasets.

**Sequence classification datasets:**

* XNLI (Conneau et al., 2018) — Natural language inference task extending MNLI (Williams et al., 2018) to non-English languages, consisting in classifying sentence pairs into entailment, contradiction, or neutral.

* PAWS-X (Yang et al., 2019) — Paraphrase identification task aimed at determining whether two sentences convey the same meaning. Fine-tuning is performed cross-lingually, with training on the English subset and evaluation across all available languages.

* AmazonReviews (Keung et al., 2020) — Sentiment analysis task consisting in estimating the satisfaction level of multilingual Amazon product reviews on a 1-to-5 scale. Fine-tuning is performed on all available languages.

* MassiveIntent (Keung et al., 2020) — Multilingual classification task consisting in assigning sentences to one of 60 topic categories. Fine-tuning is performed on all available languages.

* CodeDefect (Zhou et al., 2019) — Binary classification task aimed at identifying whether a given code snippet contains a defect.

* CodeComplexity (Jeon et al., 2023) — Computational analysis task consisting in estimating the order of complexity of a code-formulated computer science problem.

* MathShepherd (Wang et al., 2024b) — Binary classification task aimed at determining whether a step-by-step math rationale is correct given a problem prompt. We limited the dataset to rationales with 3 steps to mitigate the class imbalance observed in longer rationales, where incorrect solutions become more frequent. As the dataset lacks a validation split, we allocate half of the test set for validation.

**Sequence regression datasets:**

* WMT (Bojar et al., 2017; 2018; Barrault et al., 2019; 2020; Akhbardeh et al., 2021; Kocmi et al., 2022) — Regression task consisting in estimating translation quality given a source sentence, and possibly a reference translation. As the original test set covers only three language pairs, we construct validation and test sets by sampling 5% of the training set for each, ensuring broader language coverage in evaluation. We report results under both the reference-free and reference-based evaluation settings.

* SeaHorse (Clark et al., 2023) — Multilingual summarization evaluation task, where each text-summary pair is annotated across 6 binary evaluation dimensions. The final score is obtained by averaging these labels, yielding a continuous value between 0 and 1. To avoid penalizing models with limited context lengths, the summary is placed first in the input, followed by the main text, ensuring the model can attend to the full summary.

**Token classification datasets:**

* NER (Liang et al., 2020) — Named entity recognition task from the XGLUE benchmark, combining subsets of CoNLL2002 (Tjong Kim Sang, 2002) and CoNLL2003 (Tjong Kim Sang & De Meulder, 2003), adapted for cross-lingual evaluation with English-only training. It spans four languages (English, German, Spanish, and Dutch) and targets four entity types (Person, Location, Organization, and Miscellaneous).
E Results on larger hyper-parameter search

In this appendix, we investigate why the largest EuroBERT model does not significantly outperform its 610M counterpart on retrieval tasks. We hypothesize the larger model may benefit from a more comprehensive hyper-parameter search. To test this hypothesis, we perform a more extensive grid search for fine-tuning on the MS-MARCO dataset across the EuroBERT family. Rather than varying only the learning rate with fixed optimization settings, we systematically explore a broader set of hyperparameters: Adam's $β_2$ (0.95 [default], 0.98, 0.999), Adam's $ε$ (10⁻⁵ [default], 10⁻⁸), and the number of training steps (1,000 [default], 2,000).

<figure><img src="image_12.png" /><figcaption>Figure 8: Retrieval performance of EuroBERT models under the default fine-tuning configuration (Default) compared to the more extensive hyperparameter grid search (Extensive). Results are reported as average nDCG@10 across supported languages.</figcaption></figure>

Figure 8 demonstrates that, while all models benefit from a denser hyperparameter grid search, the largest EuroBERT model exhibits the most substantial improvements, particularly on the MIRACL and MLDR datasets. Additionally, as shown in Table 8, increasing the number of training steps from 1,000 to 2,000 consistently enhances performance across all model sizes. Also, we observe that models generally benefit from increasing $β_2$ and reducing the $ε$ and learning rate.
<table><caption>Table 8: Overview of the optimal hyperparameters selected on the validation set for both the Default and Extensive fine-tuning configurations.</caption><thead><tr><th rowspan="3">Model</th><th colspan="8">MIRACL</th></tr><tr><th colspan="2">Learning Rate</th><th colspan="2">Adam β<sub>2</sub></th><th colspan="2">Adam ε</th><th colspan="2">Steps</th></tr><tr><th>Default</th><th>Extensive</th><th>Default</th><th>Extensive</th><th>Default</th><th>Extensive</th><th>Default</th><th>Extensive</th></tr></thead><tbody><tr><td>EuroBERT-210M</td><td>4.6e-05</td><td>2.8e-05</td><td>0.95</td><td>0.98</td><td>1e-05</td><td>1e-05</td><td>1,000</td><td>2,000</td></tr><tr><td>EuroBERT-610M</td><td>3.6e-05</td><td>2.8e-05</td><td>0.95</td><td>0.98</td><td>1e-05</td><td>1e-08</td><td>1,000</td><td>1,000</td></tr><tr><td>EuroBERT-2.1B</td><td>3.6e-05</td><td>1.7e-05</td><td>0.95</td><td>0.98</td><td>1e-05</td><td>1e-08</td><td>1,000</td><td>2,000</td></tr><tr><th colspan="9">MLDR</th></tr><tr><th rowspan="2">Model</th><th colspan="2">Learning Rate</th><th colspan="2">Adam β<sub>2</sub></th><th colspan="2">Adam ε</th><th colspan="2">Steps</th></tr><tr><th>Default</th><th>Extensive</th><th>Default</th><th>Extensive</th><th>Default</th><th>Extensive</th><th>Default</th><th>Extensive</th></tr><tr><td>EuroBERT-210M</td><td>2.8e-05</td><td>2.8e-05</td><td>0.95</td><td>0.98</td><td>1e-05</td><td>1e-05</td><td>1,000</td><td>2,000</td></tr><tr><td>EuroBERT-610M</td><td>2.2e-05</td><td>2.8e-05</td><td>0.95</td><td>0.95</td><td>1e-05</td><td>1e-05</td><td>1,000</td><td>2,000</td></tr><tr><td>EuroBERT-2.1B</td><td>4.6e-05</td><td>1.3e-05</td><td>0.95</td><td>0.98</td><td>1e-05</td><td>1e-08</td><td>1,000</td><td>2,000</td></tr><tr><th colspan="9">Wikipedia</th></tr><tr><th rowspan="2">Model</th><th colspan="2">Learning Rate</th><th colspan="2">Adam β<sub>2</sub></th><th colspan="2">Adam ε</th><th colspan="2">Steps</th></tr><tr><th>Default</th><th>Extensive</th><th>Default</th><th>Extensive</th><th>Default</th><th>Extensive</th><th>Default</th><th>Extensive</th></tr><tr><td>EuroBERT-210M</td><td>2.8e-05</td><td>2.2e-05</td><td>0.95</td><td>0.98</td><td>1e-05</td><td>1e-08</td><td>1,000</td><td>2,000</td></tr><tr><td>EuroBERT-610M</td><td>3.6e-05</td><td>2.2e-05</td><td>0.95</td><td>0.95</td><td>1e-05</td><td>1e-08</td><td>1,000</td><td>2,000</td></tr><tr><td>EuroBERT-2.1B</td><td>2.8e-05</td><td>2.8e-05</td><td>0.95</td><td>0.95</td><td>1e-05</td><td>1e-05</td><td>1,000</td><td>2,000</td></tr><tr><th colspan="9">CC-News</th></tr><tr><th rowspan="2">Model</th><th colspan="2">Learning Rate</th><th colspan="2">Adam β<sub>2</sub></th><th colspan="2">Adam ε</th><th colspan="2">Steps</th></tr><tr><th>Default</th><th>Extensive</th><th>Default</th><th>Extensive</th><th>Default</th><th>Extensive</th><th>Default</th><th>Extensive</th></tr><tr><td>EuroBERT-210M</td><td>4.6e-05</td><td>3.6e-05</td><td>0.95</td><td>0.98</td><td>1e-05</td><td>1e-05</td><td>1,000</td><td>2,000</td></tr><tr><td>EuroBERT-610M</td><td>4.6e-05</td><td>2.8e-05</td><td>0.95</td><td>0.95</td><td>1e-05</td><td>1e-05</td><td>1,000</td><td>2,000</td></tr><tr><td>EuroBERT-2.1B</td><td>3.6e-05</td><td>3.6e-05</td><td>0.95</td><td>0.95</td><td>1e-05</td><td>1e-05</td><td>1,000</td><td>2,000</td></tr></tbody></table>
## F Detailed Results

Table 9 and Table 10 present per-language results for the retrieval and sequence classification tasks, respectively. Table 11 and Table 12 report detailed performance on sequence regression. Finally, Table 13 provides per-language results on token classification (NER task).

<table><thead><tr><th rowspan="3">Model</th><th colspan="12">MIRACL</th><th colspan="2">Average</th></tr><tr><th colspan="6">European Languages</th><th colspan="6">Extra-European Languages</th></tr><tr><th>en</th><th>de</th><th>es</th><th>fr</th><th>it</th><th>nl</th><th>pl</th><th>pt</th><th>ar</th><th>hi</th><th>ja</th><th>ru</th><th>tr</th><th>vi</th><th>zh</th><th>Euro</th><th>World</th></tr></thead><tbody><tr><td>XLM-RoBERTa-280M</td><td>88.0</td><td>—</td><td>88.6</td><td>91.9</td><td>—</td><td>—</td><td>—</td><td>—</td><td>84.6</td><td>77.9</td><td>85.7</td><td>82.5</td><td>—</td><td>—</td><td>83.8</td><td>89.5</td><td>85.4</td></tr><tr><td>XLM-RoBERTa-560M</td><td>89.7</td><td>—</td><td>91.6</td><td>93.5</td><td>—</td><td>—</td><td>—</td><td>—</td><td>89.0</td><td>81.1</td><td>91.1</td><td>88.6</td><td>—</td><td>—</td><td>90.3</td><td>91.6</td><td>89.4</td></tr><tr><td>XLM-RoBERTa-3.5B</td><td>90.4</td><td>—</td><td>93.0</td><td>94.5</td><td>—</td><td>—</td><td>—</td><td>—</td><td>91.5</td><td>85.1</td><td>92.6</td><td>92.1</td><td>—</td><td>—</td><td>91.9</td><td>92.6</td><td>91.4</td></tr><tr><td>mDeBERTa-v3-280M</td><td>45.3</td><td>—</td><td>39.6</td><td>46.2</td><td>—</td><td>—</td><td>—</td><td>—</td><td>34.4</td><td>36.0</td><td>33.7</td><td>29.6</td><td>—</td><td>—</td><td>35.3</td><td>43.7</td><td>37.5</td></tr><tr><td>mGTE-MLM-305M</td><td>91.4</td><td>—</td><td>94.6</td><td>95.2</td><td>—</td><td>—</td><td>—</td><td>—</td><td>91.6</td><td>85.3</td><td>91.5</td><td>88.3</td><td>—</td><td>—</td><td>91.4</td><td>93.8</td><td>91.2</td></tr><tr><td>ModernBERT-150M</td><td>93.4</td><td>—</td><td>71.2</td><td>81.2</td><td>—</td><td>—</td><td>—</td><td>—</td><td>8.6</td><td>3.0</td><td>36.0</td><td>21.3</td><td>—</td><td>—</td><td>45.6</td><td>81.9</td><td>45.0</td></tr><tr><td>ModernBERT-395M</td><td>95.1</td><td>—</td><td>84.2</td><td>90.7</td><td>—</td><td>—</td><td>—</td><td>—</td><td>5.7</td><td>8.7</td><td>32.7</td><td>19.2</td><td>—</td><td>—</td><td>34.3</td><td>90.0</td><td>46.3</td></tr><tr><td><strong>EuroBERT-210M</strong></td><td>94.1</td><td>—</td><td>95.4</td><td>95.8</td><td>—</td><td>—</td><td>—</td><td>—</td><td>90.0</td><td>83.2</td><td>90.8</td><td>85.7</td><td>—</td><td>—</td><td>90.9</td><td>95.1</td><td>90.8</td></tr><tr><td><strong>EuroBERT-610M</strong></td><td>93.6</td><td>—</td><td>95.1</td><td>96.3</td><td>—</td><td>—</td><td>—</td><td>—</td><td>91.8</td><td>88.3</td><td>92.4</td><td>90.7</td><td>—</td><td>—</td><td>92.4</td><td>95.0</td><td>92.6</td></tr><tr><td><strong>EuroBERT-2.1B</strong></td><td>94.2</td><td>—</td><td>95.0</td><td>95.3</td><td>—</td><td>—</td><td>—</td><td>—</td><td>93.0</td><td>87.1</td><td>93.4</td><td>91.5</td><td>—</td><td>—</td><td>94.1</td><td>94.8</td><td>92.9</td></tr></tbody></table>

<table><thead><tr><th rowspan="3">Model</th><th colspan="12">MLDR</th><th colspan="2">Average</th></tr><tr><th colspan="6">European Languages</th><th colspan="6">Extra-European Languages</th></tr><tr><th>en</th><th>de</th><th>es</th><th>fr</th><th>it</th><th>nl</th><th>pl</th><th>pt</th><th>ar</th><th>hi</th><th>ja</th><th>ru</th><th>tr</th><th>vi</th><th>zh</th><th>Euro</th><th>World</th></tr></thead><tbody><tr><td>XLM-RoBERTa-280M</td><td>59.4</td><td>56.7</td><td>58.0</td><td>64.5</td><td>53.4</td><td>—</td><td>—</td><td>—</td><td>44.4</td><td>56.4</td><td>50.3</td><td>43.6</td><td>—</td><td>—</td><td>53.8</td><td>58.7</td><td>54.6</td></tr><tr><td>XLM-RoBERTa-560M</td><td>63.4</td><td>61.1</td><td>66.9</td><td>71.1</td><td>61.9</td><td>—</td><td>—</td><td>—</td><td>51.5</td><td>60.3</td><td>54.9</td><td>51.5</td><td>—</td><td>—</td><td>58.9</td><td>65.2</td><td>60.8</td></tr><tr><td>XLM-RoBERTa-3.5B</td><td>68.9</td><td>66.1</td><td>72.7</td><td>73.5</td><td>67.5</td><td>—</td><td>—</td><td>—</td><td>56.5</td><td>61.8</td><td>62.6</td><td>60.8</td><td>—</td><td>—</td><td>63.5</td><td>70.0</td><td>65.9</td></tr><tr><td>mDeBERTa-v3-280M</td><td>18.8</td><td>24.3</td><td>15.4</td><td>23.9</td><td>18.2</td><td>—</td><td>—</td><td>—</td><td>19.0</td><td>12.3</td><td>20.5</td><td>17.4</td><td>13.2</td><td>—</td><td>—</td><td>18.1</td><td>20.0</td><td>18.3</td></tr><tr><td>mGTE-MLM-305M</td><td>63.5</td><td>68.7</td><td>79.5</td><td>78.2</td><td>71.4</td><td>—</td><td>—</td><td>—</td><td>78.1</td><td>55.7</td><td>66.2</td><td>62.4</td><td>60.8</td><td>—</td><td>—</td><td>60.9</td><td>73.2</td><td>67.8</td></tr><tr><td>ModernBERT-150M</td><td>61.0</td><td>11.3</td><td>23.5</td><td>25.8</td><td>18.4</td><td>—</td><td>—</td><td>—</td><td>19.7</td><td>0.7</td><td>0.7</td><td>2.9</td><td>2.5</td><td>—</td><td>—</td><td>0.8</td><td>26.6</td><td>15.2</td></tr><tr><td>ModernBERT-395M</td><td>68.4</td><td>25.3</td><td>42.6</td><td>58.0</td><td>21.2</td><td>—</td><td>—</td><td>—</td><td>37.1</td><td>0.5</td><td>2.0</td><td>3.5</td><td>3.7</td><td>—</td><td>—</td><td>0.9</td><td>42.1</td><td>23.9</td></tr><tr><td><strong>EuroBERT-210M</strong></td><td>67.2</td><td>68.1</td><td>78.2</td><td>80.0</td><td>68.9</td><td>—</td><td>—</td><td>—</td><td>77.9</td><td>52.1</td><td>51.3</td><td>60.8</td><td>59.1</td><td>—</td><td>—</td><td>56.4</td><td>73.4</td><td>65.4</td></tr><tr><td><strong>EuroBERT-610M</strong></td><td>72.5</td><td>69.5</td><td>80.3</td><td>79.8</td><td>73.9</td><td>—</td><td>—</td><td>—</td><td>79.0</td><td>55.5</td><td>60.9</td><td>61.6</td><td>62.5</td><td>—</td><td>—</td><td>59.0</td><td>75.8</td><td>68.6</td></tr><tr><td><strong>EuroBERT-2.1B</strong></td><td>72.5</td><td>65.4</td><td>77.6</td><td>77.6</td><td>69.2</td><td>—</td><td>—</td><td>—</td><td>75.0</td><td>53.0</td><td>58.1</td><td>61.5</td><td>59.3</td><td>—</td><td>—</td><td>57.6</td><td>72.9</td><td>66.1</td></tr></tbody></table>

<table><thead><tr><th rowspan="3">Model</th><th colspan="12">Wikipedia</th><th colspan="2">Average</th></tr><tr><th colspan="6">European Languages</th><th colspan="6">Extra-European Languages</th></tr><tr><th>en</th><th>de</th><th>es</th><th>fr</th><th>it</th><th>nl</th><th>pl</th><th>pt</th><th>ar</th><th>hi</th><th>ja</th><th>ru</th><th>tr</th><th>vi</th><th>zh</th><th>Euro</th><th>World</th></tr></thead><tbody><tr><td>XLM-RoBERTa-280M</td><td>94.7</td><td>91.2</td><td>—</td><td>—</td><td>91.5</td><td>90.2</td><td>—</td><td>90.8</td><td>—</td><td>87.4</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>91.7</td><td>91.0</td></tr><tr><td>XLM-RoBERTa-560M</td><td>95.4</td><td>93.5</td><td>—</td><td>—</td><td>93.4</td><td>93.4</td><td>—</td><td>92.5</td><td>—</td><td>90.7</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>93.6</td><td>93.1</td></tr><tr><td>XLM-RoBERTa-3.5B</td><td>97.9</td><td>96.5</td><td>—</td><td>—</td><td>96.6</td><td>96.3</td><td>—</td><td>96.0</td><td>—</td><td>94.5</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>96.7</td><td>96.3</td></tr><tr><td>mDeBERTa-v3-280M</td><td>66.1</td><td>60.4</td><td>—</td><td>—</td><td>53.6</td><td>57.6</td><td>—</td><td>56.5</td><td>—</td><td>51.3</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>58.9</td><td>57.6</td></tr><tr><td>mGTE-MLM-305M</td><td>96.7</td><td>93.4</td><td>—</td><td>—</td><td>94.7</td><td>93.9</td><td>—</td><td>93.6</td><td>—</td><td>92.0</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>94.6</td><td>94.1</td></tr><tr><td>ModernBERT-150M</td><td>97.3</td><td>56.5</td><td>—</td><td>—</td><td>60.5</td><td>57.2</td><td>—</td><td>67.0</td><td>—</td><td>5.7</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>67.7</td><td>57.4</td></tr><tr><td>ModernBERT-395M</td><td>98.2</td><td>69.9</td><td>—</td><td>—</td><td>70.0</td><td>67.4</td><td>—</td><td>83.2</td><td>—</td><td>12.0</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>77.7</td><td>66.8</td></tr><tr><td><strong>EuroBERT-210M</strong></td><td>97.7</td><td>94.7</td><td>—</td><td>—</td><td>94.5</td><td>95.6</td><td>—</td><td>95.7</td><td>—</td><td>88.6</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>95.6</td><td>94.4</td></tr><tr><td><strong>EuroBERT-610M</strong></td><td>98.3</td><td>95.9</td><td>—</td><td>—</td><td>96.0</td><td>96.6</td><td>—</td><td>96.1</td><td>—</td><td>92.6</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>96.6</td><td>95.9</td></tr><tr><td><strong>EuroBERT-2.1B</strong></td><td>99.0</td><td>96.1</td><td>—</td><td>—</td><td>96.0</td><td>96.0</td><td>—</td><td>95.9</td><td>—</td><td>92.0</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>96.6</td><td>95.8</td></tr></tbody></table>

<table><caption>Table 9: Detailed results on multilingual retrieval tasks (nDCG@10, in %).</caption><thead><tr><th rowspan="3">Model</th><th colspan="12">CC-News</th><th colspan="2">Average</th></tr><tr><th colspan="6">European Languages</th><th colspan="6">Extra-European Languages</th></tr><tr><th>en</th><th>de</th><th>es</th><th>fr</th><th>it</th><th>nl</th><th>pl</th><th>pt</th><th>ar</th><th>hi</th><th>ja</th><th>ru</th><th>tr</th><th>vi</th><th>zh</th><th>Euro</th><th>World</th></tr></thead><tbody><tr><td>XLM-RoBERTa-280M</td><td>69.9</td><td>57.8</td><td>55.8</td><td>57.5</td><td>57.2</td><td>66.8</td><td>55.1</td><td>63.1</td><td>72.2</td><td>31.1</td><td>75.7</td><td>76.2</td><td>47.8</td><td>61.5</td><td>77.1</td><td>60.4</td><td>61.6</td></tr><tr><td>XLM-RoBERTa-560M</td><td>77.3</td><td>68.6</td><td>69.1</td><td>70.1</td><td>70.8</td><td>75.9</td><td>69.6</td><td>75.3</td><td>82.8</td><td>51.0</td><td>82.3</td><td>83.3</td><td>61.1</td><td>73.7</td><td>81.2</td><td>72.1</td><td>72.8</td></tr><tr><td>XLM-RoBERTa-3.5B</td><td>84.4</td><td>77.7</td><td>79.7</td><td>79.1</td><td>79.6</td><td>83.8</td><td>79.5</td><td>84.0</td><td>88.1</td><td>59.5</td><td>87.4</td><td>88.8</td><td>72.2</td><td>82.9</td><td>86.8</td><td>80.9</td><td>80.9</td></tr><tr><td>mDeBERTa-v3-280M</td><td>25.0</td><td>15.7</td><td>11.9</td><td>12.4</td><td>13.1</td><td>20.4</td><td>12.4</td><td>15.8</td><td>23.1</td><td>4.7</td><td>33.6</td><td>23.6</td><td>10.7</td><td>20.4</td><td>34.8</td><td>15.8</td><td>18.5</td></tr><tr><td>mGTE-MLM-305M</td><td>76.1</td><td>68.7</td><td>72.8</td><td>70.1</td><td>68.4</td><td>76.5</td><td>65.1</td><td>74.3</td><td>79.6</td><td>32.5</td><td>85.1</td><td>83.3</td><td>56.7</td><td>72.3</td><td>88.2</td><td>71.5</td><td>71.3</td></tr><tr><td>ModernBERT-150M</td><td>75.6</td><td>16.1</td><td>15.6</td><td>14.4</td><td>15.0</td><td>29.6</td><td>7.0</td><td>10.9</td><td>2.3</td><td>1.8</td><td>6.7</td><td>2.5</td><td>8.5</td><td>5.2</td><td>10.0</td><td>23.0</td><td>14.7</td></tr><tr><td>ModernBERT-395M</td><td>84.9</td><td>21.5</td><td>33.4</td><td>41.3</td><td>20.0</td><td>36.2</td><td>4.2</td><td>27.8</td><td>2.2</td><td>2.0</td><td>9.5</td><td>4.1</td><td>9.6</td><td>10.0</td><td>9.9</td><td>33.6</td><td>21.1</td></tr><tr><td><strong>EuroBERT-210M</strong></td><td>80.0</td><td>66.9</td><td>69.2</td><td>69.7</td><td>65.9</td><td>73.5</td><td>57.8</td><td>69.1</td><td>76.7</td><td>17.0</td><td>82.4</td><td>79.7</td><td>52.1</td><td>57.4</td><td>90.9</td><td>69.0</td><td>67.2</td></tr><tr><td><strong>EuroBERT-610M</strong></td><td>84.0</td><td>72.9</td><td>76.4</td><td>75.5</td><td>73.8</td><td>79.6</td><td>70.9</td><td>79.9</td><td>84.0</td><td>49.7</td><td>84.9</td><td>85.1</td><td>62.4</td><td>66.7</td><td>88.1</td><td>76.6</td><td>75.6</td></tr><tr><td><strong>EuroBERT-2.1B</strong></td><td>85.8</td><td>73.1</td><td>77.1</td><td>76.9</td><td>73.8</td><td>79.0</td><td>70.3</td><td>79.7</td><td>84.2</td><td>49.9</td><td>88.2</td><td>86.5</td><td>60.7</td><td>63.0</td><td>89.9</td><td>76.9</td><td>75.9</td></tr></tbody></table>
<table><thead><tr><th rowspan="3">Model</th><th colspan="12">XNLI</th><th colspan="2">Average</th></tr><tr><th colspan="6">European Languages</th><th colspan="6">Extra-European Languages</th><th rowspan="2">Euro</th><th rowspan="2">World</th></tr><tr><th>en</th><th>de</th><th>es</th><th>fr</th><th>it</th><th>nl</th><th>pl</th><th>pt</th><th>ar</th><th>hi</th><th>ja</th><th>ru</th><th>tr</th><th>vi</th><th>zh</th></tr></thead><tbody><tr><td>XLM-RoBERTa-280M</td><td>80.0</td><td>74.8</td><td>76.4</td><td>75.1</td><td>—</td><td>—</td><td>—</td><td>—</td><td>71.5</td><td>69.1</td><td>—</td><td>74.4</td><td>72.4</td><td>74.0</td><td>73.2</td><td>76.6</td><td>74.1</td></tr><tr><td>XLM-RoBERTa-560M</td><td>87.1</td><td>83.0</td><td>83.5</td><td>82.9</td><td>—</td><td>—</td><td>—</td><td>—</td><td>80.4</td><td>77.8</td><td>—</td><td>81.2</td><td>80.6</td><td>80.2</td><td>80.6</td><td>84.1</td><td>81.7</td></tr><tr><td>XLM-RoBERTa-3.5B</td><td>89.0</td><td>85.5</td><td>85.3</td><td>84.5</td><td>—</td><td>—</td><td>—</td><td>—</td><td>81.5</td><td>80.5</td><td>—</td><td>83.1</td><td>82.4</td><td>83.3</td><td>82.3</td><td>86.1</td><td>83.7</td></tr><tr><td>mDeBERTa-v3-280M</td><td>84.9</td><td>81.2</td><td>81.1</td><td>81.0</td><td>—</td><td>—</td><td>—</td><td>—</td><td>77.6</td><td>76.1</td><td>—</td><td>79.1</td><td>77.7</td><td>78.1</td><td>78.4</td><td>82.0</td><td>79.5</td></tr><tr><td>mGTE-MLM-305M</td><td>81.1</td><td>76.9</td><td>78.5</td><td>77.2</td><td>—</td><td>—</td><td>—</td><td>—</td><td>73.6</td><td>71.3</td><td>—</td><td>75.4</td><td>72.9</td><td>75.9</td><td>75.5</td><td>78.4</td><td>75.8</td></tr><tr><td>ModernBERT-150M</td><td>82.8</td><td>65.7</td><td>69.9</td><td>70.6</td><td>—</td><td>—</td><td>—</td><td>—</td><td>56.9</td><td>54.0</td><td>—</td><td>63.1</td><td>53.9</td><td>58.3</td><td>68.1</td><td>72.3</td><td>64.3</td></tr><tr><td>ModernBERT-395M</td><td>89.4</td><td>75.6</td><td>79.2</td><td>79.1</td><td>—</td><td>—</td><td>—</td><td>—</td><td>59.6</td><td>55.7</td><td>—</td><td>70.9</td><td>60.6</td><td>63.0</td><td>76.1</td><td>80.8</td><td>70.9</td></tr><tr><td><strong>EuroBERT-210M</strong></td><td><strong>83.5</strong></td><td><strong>77.8</strong></td><td><strong>79.4</strong></td><td><strong>78.9</strong></td><td><strong>—</strong></td><td><strong>—</strong></td><td><strong>—</strong></td><td><strong>—</strong></td><td><strong>74.3</strong></td><td><strong>70.6</strong></td><td><strong>—</strong></td><td><strong>76.6</strong></td><td><strong>74.2</strong></td><td><strong>75.1</strong></td><td><strong>75.3</strong></td><td><strong>79.9</strong></td><td><strong>76.6</strong></td></tr><tr><td><strong>EuroBERT-610M</strong></td><td><strong>87.8</strong></td><td><strong>82.9</strong></td><td><strong>84.6</strong></td><td><strong>83.6</strong></td><td><strong>—</strong></td><td><strong>—</strong></td><td><strong>—</strong></td><td><strong>—</strong></td><td><strong>79.5</strong></td><td><strong>76.7</strong></td><td><strong>—</strong></td><td><strong>82.0</strong></td><td><strong>80.3</strong></td><td><strong>80.8</strong></td><td><strong>80.7</strong></td><td><strong>84.7</strong></td><td><strong>81.9</strong></td></tr><tr><td><strong>EuroBERT-2.1B</strong></td><td><strong>89.6</strong></td><td><strong>85.5</strong></td><td><strong>86.4</strong></td><td><strong>85.8</strong></td><td><strong>—</strong></td><td><strong>—</strong></td><td><strong>—</strong></td><td><strong>—</strong></td><td><strong>82.8</strong></td><td><strong>79.9</strong></td><td><strong>—</strong></td><td><strong>83.3</strong></td><td><strong>83.0</strong></td><td><strong>82.3</strong></td><td><strong>82.3</strong></td><td><strong>86.8</strong></td><td><strong>84.1</strong></td></tr></tbody></table>

<table><thead><tr><th rowspan="3">Model</th><th colspan="12">PAWS-X</th><th colspan="2">Average</th></tr><tr><th colspan="6">European Languages</th><th colspan="6">Extra-European Languages</th><th rowspan="2">Euro</th><th rowspan="2">World</th></tr><tr><th>en</th><th>de</th><th>es</th><th>fr</th><th>it</th><th>nl</th><th>pl</th><th>pt</th><th>ar</th><th>hi</th><th>ja</th><th>ru</th><th>tr</th><th>vi</th><th>zh</th></tr></thead><tbody><tr><td>XLM-RoBERTa-280M</td><td>93.8</td><td>86.4</td><td>87.5</td><td>88.0</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>88.9</td><td>88.9</td></tr><tr><td>XLM-RoBERTa-560M</td><td>95.5</td><td>91.0</td><td>91.4</td><td>91.8</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>92.4</td><td>92.4</td></tr><tr><td>XLM-RoBERTa-3.5B</td><td>95.8</td><td>91.9</td><td>91.7</td><td>92.3</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>92.9</td><td>92.9</td></tr><tr><td>mDeBERTa-v3-280M</td><td>95.7</td><td>90.2</td><td>90.4</td><td>91.3</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>91.9</td><td>91.9</td></tr><tr><td>mGTE-MLM-305M</td><td>94.7</td><td>87.5</td><td>88.2</td><td>88.8</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>89.8</td><td>89.8</td></tr><tr><td>ModernBERT-150M</td><td>94.7</td><td>72.0</td><td>74.0</td><td>77.7</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>79.6</td><td>79.6</td></tr><tr><td>ModernBERT-395M</td><td>95.8</td><td>75.4</td><td>82.7</td><td>83.5</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>84.3</td><td>84.3</td></tr><tr><td><strong>EuroBERT-210M</strong></td><td><strong>95.6</strong></td><td><strong>86.5</strong></td><td><strong>88.7</strong></td><td><strong>88.9</strong></td><td><strong>—</strong></td><td><strong>—</strong></td><td><strong>—</strong></td><td><strong>—</strong></td><td><strong>—</strong></td><td><strong>—</strong></td><td><strong>—</strong></td><td><strong>—</strong></td><td><strong>—</strong></td><td><strong>—</strong></td><td><strong>—</strong></td><td><strong>89.9</strong></td><td><strong>89.9</strong></td></tr><tr><td><strong>EuroBERT-610M</strong></td><td><strong>95.6</strong></td><td><strong>90.0</strong></td><td><strong>91.3</strong></td><td><strong>92.0</strong></td><td><strong>—</strong></td><td><strong>—</strong></td><td><strong>—</strong></td><td><strong>—</strong></td><td><strong>—</strong></td><td><strong>—</strong></td><td><strong>—</strong></td><td><strong>—</strong></td><td><strong>—</strong></td><td><strong>—</strong></td><td><strong>—</strong></td><td><strong>92.2</strong></td><td><strong>92.2</strong></td></tr><tr><td><strong>EuroBERT-2.1B</strong></td><td><strong>96.2</strong></td><td><strong>91.6</strong></td><td><strong>91.8</strong></td><td><strong>92.5</strong></td><td><strong>—</strong></td><td><strong>—</strong></td><td><strong>—</strong></td><td><strong>—</strong></td><td><strong>—</strong></td><td><strong>—</strong></td><td><strong>—</strong></td><td><strong>—</strong></td><td><strong>—</strong></td><td><strong>—</strong></td><td><strong>—</strong></td><td><strong>93.0</strong></td><td><strong>93.0</strong></td></tr></tbody></table>

<table><thead><tr><th rowspan="3">Model</th><th colspan="12">AmazonReviews</th><th colspan="2">Average</th></tr><tr><th colspan="6">European Languages</th><th colspan="6">Extra-European Languages</th><th rowspan="2">Euro</th><th rowspan="2">World</th></tr><tr><th>en</th><th>de</th><th>es</th><th>fr</th><th>it</th><th>nl</th><th>pl</th><th>pt</th><th>ar</th><th>hi</th><th>ja</th><th>ru</th><th>tr</th><th>vi</th><th>zh</th></tr></thead><tbody><tr><td>XLM-RoBERTa-280M</td><td>64.9</td><td>65.0</td><td>60.6</td><td>60.0</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>59.0</td><td>—</td><td>—</td><td>—</td><td>56.8</td><td>62.7</td><td>61.1</td></tr><tr><td>XLM-RoBERTa-560M</td><td>66.9</td><td>67.0</td><td>62.4</td><td>61.5</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>62.1</td><td>—</td><td>—</td><td>—</td><td>58.5</td><td>64.5</td><td>63.1</td></tr><tr><td>XLM-RoBERTa-3.5B</td><td>67.1</td><td>67.8</td><td>62.4</td><td>61.5</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>63.7</td><td>—</td><td>—</td><td>—</td><td>59.2</td><td>64.7</td><td>63.6</td></tr><tr><td>mDeBERTa-v3-280M</td><td>66.4</td><td>66.1</td><td>61.6</td><td>60.6</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>60.4</td><td>—</td><td>—</td><td>—</td><td>57.7</td><td>63.7</td><td>62.1</td></tr><tr><td>mGTE-MLM-305M</td><td>65.0</td><td>65.3</td><td>60.9</td><td>59.5</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>61.2</td><td>—</td><td>—</td><td>—</td><td>57.4</td><td>62.7</td><td>61.5</td></tr><tr><td>ModernBERT-150M</td><td>66.1</td><td>61.4</td><td>57.5</td><td>57.8</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>54.2</td><td>—</td><td>—</td><td>—</td><td>53.9</td><td>60.7</td><td>58.5</td></tr><tr><td>ModernBERT-395M</td><td>67.6</td><td>64.9</td><td>60.8</td><td>60.0</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>58.2</td><td>—</td><td>—</td><td>—</td><td>57.8</td><td>63.3</td><td>61.5</td></tr><tr><td><strong>EuroBERT-210M</strong></td><td><strong>65.9</strong></td><td><strong>65.4</strong></td><td><strong>60.5</strong></td><td><strong>60.2</strong></td><td><strong>—</strong></td><td><strong>—</strong></td><td><strong>—</strong></td><td><strong>—</strong></td><td><strong>—</strong></td><td><strong>—</strong></td><td><strong>60.4</strong></td><td><strong>—</strong></td><td><strong>—</strong></td><td><strong>—</strong></td><td><strong>57.7</strong></td><td><strong>63.0</strong></td><td><strong>61.7</strong></td></tr><tr><td><strong>EuroBERT-610M</strong></td><td><strong>66.7</strong></td><td><strong>66.4</strong></td><td><strong>61.6</strong></td><td><strong>61.2</strong></td><td><strong>—</strong></td><td><strong>—</strong></td><td><strong>—</strong></td><td><strong>—</strong></td><td><strong>—</strong></td><td><strong>—</strong></td><td><strong>61.7</strong></td><td><strong>—</strong></td><td><strong>—</strong></td><td><strong>—</strong></td><td><strong>58.1</strong></td><td><strong>64.0</strong></td><td><strong>62.6</strong></td></tr><tr><td><strong>EuroBERT-2.1B</strong></td><td><strong>66.5</strong></td><td><strong>67.8</strong></td><td><strong>62.8</strong></td><td><strong>60.9</strong></td><td><strong>—</strong></td><td><strong>—</strong></td><td><strong>—</strong></td><td><strong>—</strong></td><td><strong>—</strong></td><td><strong>—</strong></td><td><strong>62.4</strong></td><td><strong>—</strong></td><td><strong>—</strong></td><td><strong>—</strong></td><td><strong>59.0</strong></td><td><strong>64.5</strong></td><td><strong>63.2</strong></td></tr></tbody></table>

<table><caption>Table 10: Detailed results on multilingual sequence classification tasks (accuracy, in %).</caption><thead><tr><th rowspan="3">Model</th><th colspan="12">MassiveIntent</th><th colspan="2">Average</th></tr><tr><th colspan="6">European Languages</th><th colspan="6">Extra-European Languages</th><th rowspan="2">Euro</th><th rowspan="2">World</th></tr><tr><th>en</th><th>de</th><th>es</th><th>fr</th><th>it</th><th>nl</th><th>pl</th><th>pt</th><th>ar</th><th>hi</th><th>ja</th><th>ru</th><th>tr</th><th>vi</th><th>zh</th></tr></thead><tbody><tr><td>XLM-RoBERTa-280M</td><td>89.1</td><td>86.1</td><td>87.0</td><td>86.6</td><td>87.5</td><td>87.5</td><td>86.8</td><td>87.3</td><td>79.0</td><td>86.2</td><td>86.5</td><td>87.3</td><td>85.6</td><td>86.7</td><td>86.0</td><td>87.2</td><td>86.3</td></tr><tr><td>XLM-RoBERTa-560M</td><td>90.3</td><td>87.7</td><td>88.0</td><td>89.0</td><td>88.5</td><td>89.1</td><td>88.8</td><td>88.8</td><td>83.5</td><td>88.1</td><td>88.9</td><td>89.0</td><td>87.8</td><td>88.9</td><td>87.1</td><td>88.8</td><td>88.2</td></tr><tr><td>XLM-RoBERTa-3.5B</td><td>89.9</td><td>87.6</td><td>88.2</td><td>88.6</td><td>88.7</td><td>88.3</td><td>87.9</td><td>88.6</td><td>81.8</td><td>88.0</td><td>88.4</td><td>89.2</td><td>87.8</td><td>88.4</td><td>86.9</td><td>88.5</td><td>87.9</td></tr><tr><td>mDeBERTa-v3-280M</td><td>88.1</td><td>86.4</td><td>86.9</td><td>87.3</td><td>87.6</td><td>88.0</td><td>87.0</td><td>86.9</td><td>79.8</td><td>86.0</td><td>87.3</td><td>87.3</td><td>85.9</td><td>86.5</td><td>85.9</td><td>87.3</td><td>86.5</td></tr><tr><td>mGTE-MLM-305M</td><td>89.0</td><td>86.3</td><td>87.4</td><td>87.9</td><td>87.2</td><td>87.9</td><td>86.3</td><td>87.8</td><td>80.7</td><td>86.6</td><td>87.9</td><td>87.8</td><td>86.4</td><td>87.4</td><td>86.3</td><td>87.5</td><td>86.9</td></tr><tr><td>ModernBERT-150M</td><td>85.5</td><td>74.8</td><td>76.6</td><td>79.4</td><td>75.1</td><td>74.2</td><td>71.1</td><td>78.2</td><td>57.6</td><td>56.1</td><td>76.6</td><td>74.4</td><td>62.3</td><td>66.3</td><td>79.9</td><td>76.9</td><td>72.6</td></tr><tr><td>ModernBERT-395M</td><td>89.8</td><td>83.9</td><td>84.9</td><td>86.9</td><td>84.7</td><td>84.1</td><td>82.4</td><td>86.0</td><td>72.5</td><td>76.7</td><td>84.4</td><td>83.9</td><td>79.6</td><td>80.8</td><td>84.9</td><td>85.3</td><td>83.0</td></tr><tr><td><strong>EuroBERT-210M</strong></td><td><strong>89.0</strong></td><td><strong>86.0</strong></td><td><strong>86.9</strong></td><td><strong>86.9</strong></td><td><strong>87.0</strong></td><td><strong>87.1</strong></td><td><strong>86.8</strong></td><td><strong>87.9</strong></td><td><strong>81.2</strong></td><td><strong>86.9</strong></td><td><strong>87.4</strong></td><td><strong>87.2</strong></td><td><strong>85.8</strong></td><td><strong>85.0</strong></td><td><strong>86.0</strong></td><td><strong>87.2</strong></td><td><strong>86.5</strong></td></tr><tr><td><strong>EuroBERT-610M</strong></td><td><strong>89.2</strong></td><td><strong>86.6</strong></td><td><strong>87.4</strong></td><td><strong>87.6</strong></td><td><strong>88.1</strong></td><td><strong>88.2</strong></td><td><strong>87.3</strong></td><td><strong>87.8</strong></td><td><strong>82.7</strong></td><td><strong>87.3</strong></td><td><strong>88.3</strong></td><td><strong>88.2</strong></td><td><strong>86.8</strong></td><td><strong>86.1</strong></td><td><strong>87.0</strong></td><td><strong>87.8</strong></td><td><strong>87.2</strong></td></tr><tr><td><strong>EuroBERT-2.1B</strong></td><td><strong>88.9</strong></td><td><strong>87.2</strong></td><td><strong>88.0</strong></td><td><strong>88.7</strong></td><td><strong>87.9</strong></td><td><strong>88.2</strong></td><td><strong>88.1</strong></td><td><strong>88.2</strong></td><td><strong>83.2</strong></td><td><strong>87.6</strong></td><td><strong>89.0</strong></td><td><strong>88.1</strong></td><td><strong>87.1</strong></td><td><strong>85.4</strong></td><td><strong>87.0</strong></td><td><strong>88.2</strong></td><td><strong>87.5</strong></td></tr></tbody></table>
<table><caption>Table 11: Detailed results on the WMT tasks (Spearman rank correlation, in %).</caption><thead><tr><th rowspan="3">Model</th><th colspan="12">Ref-free</th><th colspan="2">Average</th></tr><tr><th colspan="6">European Pairs</th><th colspan="6">Extra-European Pairs</th></tr><tr><th colspan="2">en-xx</th><th colspan="2">xx-en</th><th colspan="2">Other</th><th colspan="2">en-xx</th><th colspan="2">xx-en</th><th colspan="2">Average</th></tr><tr><th>en-de</th><th>en-pl</th><th>de-en</th><th>pl-en</th><th>de-fr</th><th>fr-de</th><th>en-ja</th><th>en-ru</th><th>en-tr</th><th>en-zh</th><th>ja-en</th><th>ru-en</th><th>tr-en</th><th>zh-en</th><th>Euro</th><th>World</th></tr></thead><tbody><tr><td>XLM-RoBERTa-280M</td><td>45.3</td><td>53.6</td><td>26.7</td><td>16.3</td><td>31.4</td><td>32.0</td><td>47.0</td><td>56.5</td><td>61.5</td><td>42.5</td><td>10.4</td><td>21.8</td><td>40.7</td><td>25.3</td><td>34.2</td><td>36.5</td></tr><tr><td>XLM-RoBERTa-560M</td><td>50.7</td><td>66.0</td><td>30.7</td><td>15.8</td><td>41.1</td><td>29.8</td><td>52.1</td><td>61.2</td><td>66.2</td><td>47.2</td><td>11.0</td><td>24.8</td><td>45.4</td><td>29.0</td><td>39.0</td><td>40.8</td></tr><tr><td>XLM-RoBERTa-3.5B</td><td>55.1</td><td>66.9</td><td>35.9</td><td>18.7</td><td>46.7</td><td>43.3</td><td>56.3</td><td>64.9</td><td>64.8</td><td>52.2</td><td>13.1</td><td>27.0</td><td>47.7</td><td>30.6</td><td>44.4</td><td>44.5</td></tr><tr><td>mDeBERTa-v3-280M</td><td>52.8</td><td>61.6</td><td>33.1</td><td>18.3</td><td>44.4</td><td>39.6</td><td>51.6</td><td>61.2</td><td>67.2</td><td>46.7</td><td>11.2</td><td>24.2</td><td>47.3</td><td>28.9</td><td>41.6</td><td>42.0</td></tr><tr><td>mGTE-MLM-305M</td><td>48.6</td><td>55.2</td><td>30.4</td><td>18.5</td><td>37.5</td><td>35.9</td><td>48.3</td><td>57.2</td><td>59.7</td><td>45.5</td><td>10.6</td><td>23.4</td><td>41.5</td><td>27.3</td><td>37.7</td><td>38.5</td></tr><tr><td>ModernBERT-150M</td><td>39.7</td><td>47.4</td><td>29.8</td><td>18.2</td><td>20.5</td><td>21.9</td><td>36.0</td><td>41.6</td><td>39.6</td><td>37.8</td><td>10.7</td><td>21.5</td><td>41.3</td><td>23.9</td><td>29.6</td><td>30.7</td></tr><tr><td>ModernBERT-395M</td><td>45.3</td><td>51.7</td><td>32.4</td><td>20.0</td><td>23.8</td><td>27.6</td><td>37.8</td><td>44.7</td><td>43.6</td><td>41.5</td><td>12.3</td><td>24.1</td><td>42.7</td><td>27.1</td><td>33.5</td><td>33.9</td></tr><tr><td><strong>EuroBERT-210M</strong></td><td><strong>52.9</strong></td><td><strong>58.4</strong></td><td><strong>33.2</strong></td><td><strong>17.5</strong></td><td><strong>40.6</strong></td><td><strong>40.3</strong></td><td><strong>51.1</strong></td><td><strong>57.9</strong></td><td><strong>57.3</strong></td><td><strong>48.3</strong></td><td><strong>14.3</strong></td><td><strong>26.7</strong></td><td><strong>44.3</strong></td><td><strong>30.8</strong></td><td><strong>40.5</strong></td><td><strong>41.0</strong></td></tr><tr><td><strong>EuroBERT-610M</strong></td><td><strong>52.9</strong></td><td><strong>61.1</strong></td><td><strong>32.4</strong></td><td><strong>18.2</strong></td><td><strong>42.6</strong></td><td><strong>39.2</strong></td><td><strong>51.3</strong></td><td><strong>59.4</strong></td><td><strong>62.3</strong></td><td><strong>48.6</strong></td><td><strong>12.2</strong></td><td><strong>26.6</strong></td><td><strong>44.1</strong></td><td><strong>29.7</strong></td><td><strong>41.1</strong></td><td><strong>41.5</strong></td></tr><tr><td><strong>EuroBERT-2.1B</strong></td><td><strong>49.1</strong></td><td><strong>57.8</strong></td><td><strong>29.8</strong></td><td><strong>19.3</strong></td><td><strong>38.3</strong></td><td><strong>38.5</strong></td><td><strong>47.8</strong></td><td><strong>56.9</strong></td><td><strong>56.5</strong></td><td><strong>45.0</strong></td><td><strong>10.7</strong></td><td><strong>23.5</strong></td><td><strong>41.3</strong></td><td><strong>27.5</strong></td><td><strong>38.8</strong></td><td><strong>38.7</strong></td></tr></tbody></table><table><thead><tr><th rowspan="3">Model</th><th colspan="12">Ref-based</th><th colspan="2">Average</th></tr><tr><th colspan="6">European Pairs</th><th colspan="6">Extra-European Pairs</th></tr><tr><th colspan="2">en-xx</th><th colspan="2">xx-en</th><th colspan="2">Other</th><th colspan="2">en-xx</th><th colspan="2">xx-en</th><th colspan="2">Average</th></tr><tr><th>en-de</th><th>en-pl</th><th>de-en</th><th>pl-en</th><th>de-fr</th><th>fr-de</th><th>en-ja</th><th>en-ru</th><th>en-tr</th><th>en-zh</th><th>ja-en</th><th>ru-en</th><th>tr-en</th><th>zh-en</th><th>Euro</th><th>World</th></tr></thead><tbody><tr><td>XLM-RoBERTa-280M</td><td>49.6</td><td>56.0</td><td>34.4</td><td>29.2</td><td>47.8</td><td>41.9</td><td>49.8</td><td>60.5</td><td>63.1</td><td>50.1</td><td>14.2</td><td>25.3</td><td>48.7</td><td>31.1</td><td>43.1</td><td>43.0</td></tr><tr><td>XLM-RoBERTa-560M</td><td>52.3</td><td>63.9</td><td>37.3</td><td>26.8</td><td>51.1</td><td>42.3</td><td>53.6</td><td>63.3</td><td>70.9</td><td>53.0</td><td>12.6</td><td>25.2</td><td>49.2</td><td>32.3</td><td>45.6</td><td>45.3</td></tr><tr><td>XLM-RoBERTa-3.5B</td><td>55.9</td><td>68.2</td><td>39.1</td><td>28.2</td><td>53.7</td><td>45.6</td><td>56.7</td><td>66.3</td><td>71.1</td><td>55.2</td><td>12.8</td><td>28.9</td><td>52.4</td><td>34.0</td><td>48.5</td><td>47.7</td></tr><tr><td>mDeBERTa-v3-280M</td><td>53.0</td><td>65.6</td><td>37.6</td><td>27.9</td><td>50.9</td><td>43.7</td><td>52.7</td><td>63.5</td><td>69.1</td><td>53.0</td><td>13.1</td><td>27.8</td><td>49.9</td><td>32.5</td><td>46.5</td><td>45.7</td></tr><tr><td>mGTE-MLM-305M</td><td>51.0</td><td>57.4</td><td>36.6</td><td>29.9</td><td>49.6</td><td>39.3</td><td>51.5</td><td>61.8</td><td>63.5</td><td>52.4</td><td>13.8</td><td>26.0</td><td>48.7</td><td>32.8</td><td>44.0</td><td>43.9</td></tr><tr><td>ModernBERT-150M</td><td>43.5</td><td>50.2</td><td>36.8</td><td>28.2</td><td>42.5</td><td>33.1</td><td>45.4</td><td>50.4</td><td>54.2</td><td>46.0</td><td>13.8</td><td>26.6</td><td>50.8</td><td>31.7</td><td>39.1</td><td>39.5</td></tr><tr><td>ModernBERT-395M</td><td>47.4</td><td>53.9</td><td>39.2</td><td>31.6</td><td>43.5</td><td>34.8</td><td>47.1</td><td>52.3</td><td>60.0</td><td>48.6</td><td>14.9</td><td>28.9</td><td>53.1</td><td>34.0</td><td>41.7</td><td>42.1</td></tr><tr><td><strong>EuroBERT-210M</strong></td><td><strong>52.5</strong></td><td><strong>59.8</strong></td><td><strong>38.8</strong></td><td><strong>30.5</strong></td><td><strong>49.7</strong></td><td><strong>39.6</strong></td><td><strong>52.2</strong></td><td><strong>61.5</strong></td><td><strong>65.9</strong></td><td><strong>53.1</strong></td><td><strong>15.2</strong></td><td><strong>28.7</strong></td><td><strong>50.5</strong></td><td><strong>34.7</strong></td><td><strong>45.1</strong></td><td><strong>45.2</strong></td></tr><tr><td><strong>EuroBERT-610M</strong></td><td><strong>53.8</strong></td><td><strong>64.0</strong></td><td><strong>37.8</strong></td><td><strong>29.4</strong></td><td><strong>51.3</strong></td><td><strong>42.5</strong></td><td><strong>53.2</strong></td><td><strong>62.9</strong></td><td><strong>67.9</strong></td><td><strong>52.3</strong></td><td><strong>16.2</strong></td><td><strong>29.2</strong></td><td><strong>50.6</strong></td><td><strong>33.5</strong></td><td><strong>46.5</strong></td><td><strong>46.0</strong></td></tr><tr><td><strong>EuroBERT-2.1B</strong></td><td><strong>54.9</strong></td><td><strong>65.7</strong></td><td><strong>39.4</strong></td><td><strong>31.0</strong></td><td><strong>54.9</strong></td><td><strong>45.0</strong></td><td><strong>55.0</strong></td><td><strong>64.3</strong></td><td><strong>68.3</strong></td><td><strong>54.5</strong></td><td><strong>14.9</strong></td><td><strong>28.3</strong></td><td><strong>52.0</strong></td><td><strong>34.3</strong></td><td><strong>48.5</strong></td><td><strong>47.3</strong></td></tr></tbody></table>

<table><caption>Table 12: Detailed results on the SeaHorse summary evaluation task (Spearman rank correlation, in %).</caption><thead><tr><th rowspan="2">Model</th><th colspan="10">European Languages</th><th colspan="6">Extra-European Languages</th><th colspan="2">Average</th></tr><tr><th>en</th><th>de</th><th>es</th><th>fr</th><th>it</th><th>nl</th><th>pl</th><th>pt</th><th>ar</th><th>hi</th><th>ja</th><th>ru</th><th>tr</th><th>vi</th><th>zh</th><th>Euro</th><th>World</th></tr></thead><tbody><tr><td>XLM-RoBERTa-280M</td><td>53.2</td><td>55.6</td><td>62.0</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>69.1</td><td>67.3</td><td>59.3</td><td>—</td><td>56.9</td><td>61.1</td></tr><tr><td>XLM-RoBERTa-560M</td><td>57.1</td><td>60.1</td><td>66.9</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>73.6</td><td>72.6</td><td>62.7</td><td>—</td><td>61.4</td><td>65.5</td></tr><tr><td>XLM-RoBERTa-3.5B</td><td>58.1</td><td>62.1</td><td>69.7</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>75.6</td><td>75.5</td><td>64.0</td><td>—</td><td>63.3</td><td>67.5</td></tr><tr><td>mDeBERTa-v3-280M</td><td>56.2</td><td>58.5</td><td>66.3</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>72.6</td><td>71.9</td><td>59.6</td><td>—</td><td>60.3</td><td>64.2</td></tr><tr><td>mGTE-MLM-305M</td><td>52.7</td><td>58.6</td><td>66.3</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>69.7</td><td>69.6</td><td>61.4</td><td>—</td><td>59.2</td><td>63.0</td></tr><tr><td>ModernBERT-150M</td><td>44.6</td><td>47.9</td><td>52.8</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>59.6</td><td>53.8</td><td>52.1</td><td>—</td><td>48.4</td><td>51.8</td></tr><tr><td>ModernBERT-395M</td><td>56.9</td><td>56.8</td><td>64.0</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>66.7</td><td>65.6</td><td>59.0</td><td>—</td><td>59.3</td><td>61.5</td></tr><tr><td><strong>EuroBERT-210M</strong></td><td><strong>54.4</strong></td><td><strong>58.7</strong></td><td><strong>67.2</strong></td><td><strong>—</strong></td><td><strong>—</strong></td><td><strong>—</strong></td><td><strong>—</strong></td><td><strong>—</strong></td><td><strong>—</strong></td><td><strong>—</strong></td><td><strong>—</strong></td><td><strong>70.0</strong></td><td><strong>71.2</strong></td><td><strong>61.3</strong></td><td><strong>—</strong></td><td><strong>60.1</strong></td><td><strong>63.8</strong></td></tr><tr><td><strong>EuroBERT-610M</strong></td><td><strong>57.2</strong></td><td><strong>60.6</strong></td><td><strong>70.3</strong></td><td><strong>—</strong></td><td><strong>—</strong></td><td><strong>—</strong></td><td><strong>—</strong></td><td><strong>—</strong></td><td><strong>—</strong></td><td><strong>—</strong></td><td><strong>—</strong></td><td><strong>72.6</strong></td><td><strong>73.5</strong></td><td><strong>61.5</strong></td><td><strong>—</strong></td><td><strong>62.7</strong></td><td><strong>66.0</strong></td></tr><tr><td><strong>EuroBERT-2.1B</strong></td><td><strong>58.8</strong></td><td><strong>62.1</strong></td><td><strong>71.1</strong></td><td><strong>—</strong></td><td><strong>—</strong></td><td><strong>—</strong></td><td><strong>—</strong></td><td><strong>—</strong></td><td><strong>—</strong></td><td><strong>—</strong></td><td><strong>—</strong></td><td><strong>74.4</strong></td><td><strong>75.7</strong></td><td><strong>62.8</strong></td><td><strong>—</strong></td><td><strong>64.0</strong></td><td><strong>67.5</strong></td></tr></tbody></table>

<table><caption>Table 13: Detailed results on the NER task (F1 score, in %).</caption><thead><tr><th rowspan="2">Model</th><th colspan="10">European Languages</th><th colspan="6">Extra-European Languages</th><th colspan="2">Average</th></tr><tr><th>en</th><th>de</th><th>es</th><th>fr</th><th>it</th><th>nl</th><th>pl</th><th>pt</th><th>ar</th><th>hi</th><th>ja</th><th>ru</th><th>tr</th><th>vi</th><th>zh</th><th>Euro</th><th>World</th></tr></thead><tbody><tr><td>XLM-RoBERTa-280M</td><td>97.6</td><td>94.5</td><td>93.6</td><td>—</td><td>—</td><td>96.1</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>95.5</td><td>95.5</td></tr><tr><td>XLM-RoBERTa-560M</td><td>97.7</td><td>96.4</td><td>93.9</td><td>—</td><td>—</td><td>96.2</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>96.1</td><td>96.1</td></tr><tr><td>XLM-RoBERTa-3.5B</td><td>98.3</td><td>96.4</td><td>94.5</td><td>—</td><td>—</td><td>96.1</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>96.3</td><td>96.3</td></tr><tr><td>mDeBERTa-v3-280M</td><td>98.1</td><td>96.4</td><td>94.2</td><td>—</td><td>—</td><td>96.1</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>96.2</td><td>96.2</td></tr><tr><td>mGTE-MLM-305M</td><td>97.9</td><td>94.0</td><td>93.0</td><td>—</td><td>—</td><td>95.7</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>95.2</td><td>95.2</td></tr><tr><td>ModernBERT-150M</td><td>84.0</td><td>89.4</td><td>89.8</td><td>—</td><td>—</td><td>92.8</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>89.0</td><td>89.0</td></tr><tr><td>ModernBERT-395M</td><td>97.8</td><td>81.5</td><td>92.5</td><td>—</td><td>—</td><td>94.6</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>91.6</td><td>91.6</td></tr><tr><td><strong>EuroBERT-210M</strong></td><td><strong>97.7</strong></td><td><strong>91.8</strong></td><td><strong>93.8</strong></td><td><strong>—</strong></td><td><strong>—</strong></td><td><strong>95.5</strong></td><td><strong>—</strong></td><td><strong>—</strong></td><td><strong>—</strong></td><td><strong>—</strong></td><td><strong>—</strong></td><td><strong>—</strong></td><td><strong>—</strong></td><td><strong>—</strong></td><td><strong>—</strong></td><td><strong>94.7</strong></td><td><strong>94.7</strong></td></tr><tr><td><strong>EuroBERT-610M</strong></td><td><strong>97.6</strong></td><td><strong>96.0</strong></td><td><strong>94.0</strong></td><td><strong>—</strong></td><td><strong>—</strong></td><td><strong>95.8</strong></td><td><strong>—</strong></td><td><strong>—</strong></td><td><strong>—</strong></td><td><strong>—</strong></td><td><strong>—</strong></td><td><strong>—</strong></td><td><strong>—</strong></td><td><strong>—</strong></td><td><strong>—</strong></td><td><strong>95.9</strong></td><td><strong>95.9</strong></td></tr><tr><td><strong>EuroBERT-2.1B</strong></td><td><strong>97.6</strong></td><td><strong>94.2</strong></td><td><strong>93.8</strong></td><td><strong>—</strong></td><td><strong>—</strong></td><td><strong>95.0</strong></td><td><strong>—</strong></td><td><strong>—</strong></td><td><strong>—</strong></td><td><strong>—</strong></td><td><strong>—</strong></td><td><strong>—</strong></td><td><strong>—</strong></td><td><strong>—</strong></td><td><strong>—</strong></td><td><strong>95.2</strong></td><td><strong>95.2</strong></td></tr></tbody></table>