Liquid AI
Try LFM • Docs • Discord

LFM2.5-24B-A2B-Base

LFM2.5 is a new family of hybrid models designed for on-device deployment. LFM2.5-24B-A2B is the largest model in the family: a 24B-parameter mixture of experts with only 2B active parameters. It builds on LFM2-24B-A2B with a 131K context window, a vocabulary doubled to 128K tokens, and pre-training scaled up from ~17T to ~33T tokens.

Find more information about LFM2.5-24B-A2B in our blog post.

🗒️ Model Details

Model Parameters Description
LFM2.5-24B-A2B-Base 24B (2B active) Pre-trained base model for fine-tuning
LFM2.5-24B-A2B 24B (2B active) Post-trained for agentic workloads

LFM2.5-24B-A2B-Base is the pre-trained text-only checkpoint, used to create all the LFM2.5-24B-A2B variants. It has the following features:

  • Total parameters: 24.0B
  • Active parameters: 2.45B
  • Number of layers: 40 (30 double-gated short convolution blocks + 10 GQA)
  • Experts: 64 per MoE block, top-4 routing
  • Training budget: 36 trillion tokens
  • Vocabulary size: 128,000
  • Context length: 131,072 tokens
  • Languages: English, Arabic, Chinese, French, German, Italian, Japanese, Korean, Portuguese, Spanish, Vietnamese, Thai, Indonesian, Hindi, Russian, Polish

Pre-training is followed by two mid-training phases: 2T tokens at 32K context on curated data weighted toward reasoning, math, code, instruction following, and multilingual text, then 300B tokens at 131K context weighted toward long-context data. Tool calls and multi-turn trajectories appear throughout both phases to prepare the model for agentic workloads.

This pre-trained checkpoint is only recommended for tasks that require heavy fine-tuning, like language-specific (e.g., Japanese) or domain-specific (e.g., medical) assistants, training on proprietary data, or experimenting with novel post-training approaches. Other checkpoints to consider for your use case:

Model Description
LFM2.5-24B-A2B Original post-trained model checkpoint in native format. Best for fine-tuning or inference with Transformers, vLLM, and SGLang.
LFM2.5-24B-A2B-GGUF Quantized format for llama.cpp and compatible tools. Optimized for CPU inference and local deployment with reduced memory usage.
LFM2.5-24B-A2B-ONNX ONNX Runtime format for cross-platform deployment. Enables hardware-accelerated inference across diverse environments (cloud, edge, mobile).
LFM2.5-24B-A2B-MLX MLX format for Apple Silicon. Optimized for fast inference on Mac devices using the MLX framework.

🏃 Inference

LFM2.5 is supported by many inference frameworks. See the Inference documentation for the full list.

Name Description Docs Notebook
Transformers Simple inference with direct access to model internals. Link Colab link
vLLM High-throughput production deployments with GPU. Link Colab link
llama.cpp Cross-platform inference with CPU offloading. Link Colab link
MLX Apple's machine learning framework optimized for Apple Silicon. Link —
LM Studio Desktop application for running LLMs locally. Link —
SGLang High-throughput production deployments with GPU. Link -

Quick start with Transformers (compatible with transformers>=5.0.0):

from transformers import AutoModelForCausalLM, AutoTokenizer, TextStreamer

model_id = "LiquidAI/LFM2.5-24B-A2B-Base"
model = AutoModelForCausalLM.from_pretrained(
    model_id,
    device_map="auto",
    dtype="bfloat16",
#   attn_implementation="flash_attention_2" <- uncomment on compatible GPU
)
tokenizer = AutoTokenizer.from_pretrained(model_id)
streamer = TextStreamer(tokenizer, skip_prompt=True, skip_special_tokens=True)

prompt = "What is C. elegans?"

input_ids = tokenizer.apply_chat_template(
    [{"role": "user", "content": prompt}],
    add_generation_prompt=True,
    return_tensors="pt",
    tokenize=True,
)["input_ids"].to(model.device)

output = model.generate(
    input_ids,
    max_new_tokens=512,
    streamer=streamer,
)

🔧 Fine-Tuning

We recommend fine-tuning LFM2.5 for your specific use case to achieve the best results.

Name Description Docs Notebook
CPT (Unsloth) Continued Pre-Training using Unsloth for text completion. Link Colab link
CPT (Unsloth) Continued Pre-Training using Unsloth for translation. Link Colab link
SFT (Unsloth) Supervised Fine-Tuning with LoRA using Unsloth. Link Colab link
SFT (TRL) Supervised Fine-Tuning with LoRA using TRL. Link Colab link
DPO (TRL) Direct Preference Optimization with LoRA using TRL. Link Colab link
GRPO (Unsloth) GRPO with LoRA using Unsloth. Link Colab link
GRPO (TRL) GRPO with LoRA using TRL. Link Colab link

📬 Contact

Citation

@article{liquidAI202624BA2B,
  author  = {Liquid AI},
  title   = {LFM2.5-24B-A2B: Built for Fast On-Device Agents},
  journal = {Liquid AI Blog},
  year    = {2026},
  note    = {www.liquid.ai/blog/lfm2-5-24b-a2b},
}
@article{liquidai2025lfm2,
  title   = {LFM2 Technical Report},
  author  = {Liquid AI},
  journal = {arXiv preprint arXiv:2511.23404},
  year    = {2025}
}
Downloads last month
7
Safetensors
Model size
24B params
Tensor type
F32
·
BF16
·
Inference Providers NEW
This model isn't deployed by any Inference Provider. 🙋 Ask for provider support

Model tree for LiquidAI/LFM2.5-24B-A2B-Base

Finetunes
2 models

Paper for LiquidAI/LFM2.5-24B-A2B-Base

Article mentioning LiquidAI/LFM2.5-24B-A2B-Base