How to Choose a Vector Database (2026)
A decision framework based on the objective characteristics of each tool (type, self-hosting, managed options, scale). Pick the branch that matches your situation.
Decision tree
- Already running Postgres & moderate data? → pgvector — no new infrastructure, vectors live next to your relational data.
- Want zero ops, fully managed? → Pinecone (managed-only), or the managed tiers of Qdrant / Weaviate / Zilliz.
- Self-host at production scale? → Qdrant / Milvus / Weaviate — see the production ranking.
- Local prototype or embedded? → Chroma / LanceDB — lightweight, low ops.
- Just need a library (no server)? → FAISS — research-grade ANN, you manage storage.
- Building RAG specifically? → see best for RAG (filtering + hybrid search matter most).
What to compare
Beyond popularity, weigh: self-hostable vs managed-only (lock-in & cost), license, metadata filtering / hybrid search (critical for RAG), and operational overhead. Live numbers for every tool are on the full ranking.