The best vector databases for AI agents

Cloud-native vector database built for billion-scale similarity search. Best for billion-scale search.

In-process analytical database whose vss extension adds an HNSW vector index — vector search alongside your columnar analytics. Best for analytical + vector search.

High-performance vector search engine with rich filtering, written in Rust for production-scale retrieval. Best for production RAG.

Open-source embedding database designed for simplicity — the default vector store for many RAG prototypes. Best for RAG.

Vector similarity search inside Postgres — keep embeddings next to your relational data. Best for RAG on existing Postgres.

Open-source vector database with hybrid search and built-in modules for vectorization and RAG. Best for hybrid search.

Embedded, in-process vector database on the columnar Lance format — versioned, updatable, larger-than-RAM retrieval with no server. Best for embedded vector search.

A single-file SQLite extension for vector search — exact brute-force KNN that lives inside the database you already ship. Best for vectors inside SQLite.