Chroma "Collection Not Found" Error
Workaround available Python, JavaScript, Docker Updated November 15, 2026Based on 2 user reportsHow we research
Quick answer
Usually the collection lived in memory and was lost, or you hit a different path or server. Use a persistent client and get_or_create_collection.
Most likely fix: Persist and use get_or_create
How to fix it
Try these in order — the most common fix is first.
1. Persist and use get_or_create
- Use PersistentClient with a fixed path
- Call get_or_create_collection(name)
Did this fix it?2. Match versions
- Pin chromadb client and server to the same version
- Check the server version via client.get_version()
Did this fix it?
Symptoms
ValueError: Collection my_collection does not exist, or a 404 on collection calls.
Why it happens
- In-memory client lost the data
- Pointing at the wrong persist path
- Client and server on different Chroma versions
This guide also covers
- chromadb collection not found
- chroma collection does not exist
- chromadb 404 collection
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