Continuous Autoregressive Language Models
Authors: name: Chenze Shao; name: Darren Li; name: Fandong Meng; name: Jie Zhou
Published: 2025-10-31 17:58:11

Abstract: The efficiency of large language models (LLMs) is fundamentally limited by
their sequential, token-by-token generation process. We argue that overcoming
this bottleneck requires a new design axis for LLM scaling: increasing the
semantic bandwidth of each generative step. To this end, we introduce
Continuous Autoregressive Language Models (CALM), a paradigm shift from
discrete next-token prediction to continuous next-vector prediction. CALM uses
a high-fidelity autoencoder to compress a chunk of K tokens into a single
continuous vector, from which the original tokens can be reconstructed with
over 99.9\% accuracy. This allows us to model language as a sequence of
continuous vectors instead of discrete tokens, which reduces the number of
generative steps by a factor of K. The paradigm shift necessitates a new
modeling toolkit; therefore, we develop a comprehensive likelihood-free
framework that enables robust training, evaluation, and controllable sampling
in the continuous domain. Experiments show that CALM significantly improves the
performance-compute trade-off, achieving the performance of strong discrete
baselines at a significantly lower computational cost. More importantly, these
findings establish next-vector prediction as a powerful and scalable pathway
towards ultra-efficient language models. Code:
https://github.com/shaochenze/calm. Project:
https://shaochenze.github.io/blog/2025/CALM.