Qdrant "Wrong input: Vector dimension error: expected dim, got"

Share
Ongoing Self-hosted, Qdrant Cloud Updated November 14, 2026Based on 4 user reportsHow we research

Quick answer

The collection has a fixed vector size and the vector you sent has a different length. Match the embedding model output to the collection size, or recreate the collection and re-embed.

Most likely fix: Compare the two numbers in the error

How to fix it

Try these in order — the most common fix is first.

  1. 1. Compare the two numbers in the error

    1. "expected dim" is the collection size, "got" is your embedding length
    2. Open the collection info (GET /collections/<name>) and check vectors.size
    Did this fix it?
  2. 2. Make the embedding model output match

    1. Set the same model and the same "dimensions" value for indexing and querying
    2. Restart your app so cached clients pick up the setting
    Did this fix it?
  3. 3. Recreate the collection for the new size

    1. Create a new collection with the new vector size
    2. Re-embed and upsert all documents; Qdrant cannot resize an existing collection
    3. Delete the old collection once the new one works
    Did this fix it?

Symptoms

Upsert or search returns 400 Bad Request: "Wrong input: Vector dimension error: expected dim: 768, got 1536" (or similar numbers).

Why it happens

  • Collection created with one size (for example 768) but the embedding model outputs another (1536, 3072)
  • OpenAI "dimensions" parameter set differently at index time and query time
  • Embedding model changed after the collection was created
  • Named vectors: wrong vector name used

This guide also covers

  • qdrant vector dimension error
  • qdrant expected dim got
  • qdrant wrong input vector dimension

Still not working?

If Qdrant keeps failing, you're not alone. See every Qdrant problem users report or the alternatives people switch to.

Have an app idea? Our small team builds any software: web and mobile apps, games, desktop, AI tools. Price agreed together.

Talk to us
Fixed it? Share this guide

The same problem in other apps

All not loading, error messages & connection guides →

Other Qdrant errors