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vector_db_comparison

Vector Database Comparison

A practical guide to choosing the right vector database for AI agents, RAG systems, and semantic search. Current as of Q1 2026.

Vector Database Comparison Table

Database Language Stars Hosted Option Max Vectors Filtering Hybrid Search Pricing
FAISS C++ (Python bindings) 33k No (library only) Unlimited (RAM-bound) Post-filtering only No Free / open-source
Milvus C++ / Go 35k Yes (Zilliz Cloud) Billions (distributed) Yes (scalar pre-filter) Yes (dense + sparse) Free OSS; Zilliz from $0 free tier
Qdrant Rust 25k Yes (Qdrant Cloud) Billions (on-disk + distributed) Yes (advanced payload) Yes (dense + sparse + BM25) Free OSS; Cloud from $25/mo
ChromaDB Python 18k Yes (Chroma Cloud beta) Millions (RAM-limited) Yes (metadata) Partial Free OSS; Cloud in beta
Weaviate Go 20k Yes (Weaviate Cloud) Billions (cloud-native) Yes (GraphQL filters) Yes (BM25 + vector) Free OSS; Cloud free tier available
Pinecone Proprietary N/A (closed) Yes (fully managed) Billions (serverless) Yes (metadata) Yes (sparse-dense) Pay-as-you-go; free tier 1M vectors
pgvector C (Postgres ext) 14k Via Postgres hosts Billions (with partitioning) Yes (full SQL) Partial (pair with tsvector) Free OSS; hosted via Supabase/Neon etc

When to Use Which

graph TD A["Choosing a
Vector Database"] --> B{"What stage
are you at?"} B -->|"Prototyping /
Local dev"| C{"Need persistence?"} C -->|No| C1["FAISS"] C -->|Yes| C2["ChromaDB"] B -->|"Production /
Scale"| D{"Self-host or
managed?"} D -->|"Self-hosted"| E{"Primary
requirement?"} E -->|"Performance"| E1["Qdrant"] E -->|"Scale + ecosystem"| E2["Milvus"] E -->|"GraphQL API"| E3["Weaviate"] D -->|"Fully managed"| F{"Budget?"} F -->|"Minimize ops"| F1["Pinecone"] F -->|"Cost-conscious"| F2["Qdrant Cloud or
Weaviate Cloud"] B -->|"Already using
Postgres"| G["pgvector"] style A fill:#4a90d9,color:#fff style C1 fill:#2ecc71,color:#fff style C2 fill:#2ecc71,color:#fff style E1 fill:#e67e22,color:#fff style E2 fill:#e67e22,color:#fff style E3 fill:#e67e22,color:#fff style F1 fill:#9b59b6,color:#fff style F2 fill:#9b59b6,color:#fff style G fill:#e74c3c,color:#fff

Detailed Guidance

Prototyping & Local Development

  • FAISS – Best for experimentation. Facebook's library gives you raw speed with zero infrastructure. No server needed, just pip install faiss-cpu. Downside: no persistence, no filtering, no API.
  • ChromaDB – Best for quick RAG prototypes. Embedded mode with persistence. Simple Python API. Not built for production scale.

Production Self-Hosted

  • Qdrant – Written in Rust for performance. Excellent payload filtering. On-disk storage means you can handle datasets larger than RAM. Strong hybrid search with BM25.
  • Milvus – Battle-tested at billion-scale. Horizontal scaling via distributed architecture. Zilliz Cloud for managed option. Most mature open-source vector DB.
  • Weaviate – Go-based with a rich GraphQL API. Built-in vectorization modules (no need to pre-compute embeddings). Excellent hybrid search.

Fully Managed

  • Pinecone – Zero ops. Serverless scaling. Best if you want to focus purely on your application logic. Trade-off: vendor lock-in, no self-host option.

Already Using Postgres

  • pgvector – Add vector search to your existing Postgres. No new infrastructure. Full SQL filtering. Best when vectors are a feature, not the whole product. Combine with tsvector for hybrid search.

Performance Characteristics

Database Indexing Query Latency Memory Efficiency Disk-Based
FAISS HNSW, IVF, PQ Sub-ms (in-memory) Moderate No
Milvus HNSW, IVF, DiskANN Low ms Good (segment-based) Yes
Qdrant HNSW Low ms Excellent (Rust) Yes
ChromaDB HNSW Low ms Moderate Limited
Weaviate HNSW Low ms Good Yes
Pinecone Proprietary Low ms N/A (managed) N/A
pgvector HNSW, IVFFlat Moderate ms Depends on Postgres Yes

Last updated: March 2026

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