huggingface config_error ai_generated true

ValueError: tokenizer and model vocab size mismatch

ID: huggingface/tokenizer-mismatch

Also available as: JSON · Markdown
82%Fix Rate
85%Confidence
3Evidence
2023-01-01First Seen

Version Compatibility

VersionStatusIntroducedDeprecatedNotes
4 active — — —

Root Cause

Tokenizer vocab differs from model embedding size.

generic

Workarounds

  1. 92% success Use model.resize_token_embeddings(len(tokenizer))
  2. 90% success Ensure tokenizer and model are from same checkpoint

Dead Ends

Common approaches that don't work:

  1. Ignore mismatch and train anyway 88% fail

    Crashes on out-of-range token IDs

  2. Truncate embeddings to match 80% fail

    Loses token representations