Prompt
Do I need to re-embed documents every time I change the model?
Latest observation
Oct 10, 2026
OpenAI APIWeb search: off
Usually yes — if you change the embedding model, you should re-embed your documents.
Why:
- Embeddings are vectors produced by a specific model.
- Different models create vectors in different spaces and dimensions.
- If you mix old embeddings with a new embedding model, similarity search quality will usually drop or become invalid.
When you do not need to re-embed:
- You only changed the chat/completion model (for example, GPT-4 to GPT-4.1) but kept the same embedding model.
- You changed retrieval settings like chunk size, top-k, reranking, etc., without changing embeddings.
Best practice:
- Store the embedding model name/version alongside your vectors.
- Rebuild embeddings if you:
- switch embedding models
- significantly update source documents
- change chunking strategy in a way that affects stored text units
If you want, I can also tell you:
- how to migrate embeddings safely, or
- which model changes require re-embedding vs. not.