titleScratchpad Patching: Decoupling Compute from Patch Size in Byte-Level Language Models
authorsLin Zheng, Vasilisa Bashlovkina, Timothy Dozat, Dan Garrette, Laura Rimell, Joshua Maynez
date2026-05-10
venuearXiv (preprint, not peer reviewed)
idarXiv:2605.09630
upvotes1 (Hugging Face Daily Papers, 2026-11-01)
linksabs pdf hf
abstractTokenizer-free language models eliminate the tokenizer step of the language modeling pipeline by operating directly on bytes; patch-based variants further aggregate contiguous byte spans into patches for efficiency. However, the average patch size chosen at the model design stage governs a tight trade-off: larger patches reduce compute and KV-cache footprint, but degrade modeling quality. We trace this trade-off to patch lag: until a patch is fully observed, byte predictions within it must rely on a stale representation from the previous patch to preserve causality; this lag widens as patches grow larger. We introduce Scratchpad Patching (SP), which inserts transient scratchpads inside each patch to aggregate the bytes seen so far and refresh patch-level context for subsequent predictions. SP triggers scratchpads using next-byte prediction entropy, selectively allocating compute to information-dense regions and enabling post-hoc adjustment of inference-time compute. Across experiments on natural language and code, SP improves model quality at the same patch size; for example, even at 16 bytes per patch, SP-augmented models match or closely approach the byte-level baseline on downstream evaluations while using a 16times smaller KV cache over patches and 3-4times less inference compute.

cite

@misc{zheng2026scratchpad,
  title={Scratchpad Patching: Decoupling Compute from Patch Size in Byte-Level Language Models},
  author={Lin Zheng and Vasilisa Bashlovkina and Timothy Dozat and Dan Garrette and Laura Rimell and Joshua Maynez},
  year={2026},
  eprint={2605.09630},
  archivePrefix={arXiv},
  url={https://arxiv.org/abs/2605.09630}
}