FAISS
The reference library for similarity search
Vector databaseVector search libraryMITRuns locallyC++/PythonAdvanced
🐳 Docker pulls
📦 PyPI downloads / month
📦 npm downloads / month
🚀 Latest release ·
What is FAISS?
FAISS from Meta is the foundational C++/Python library for efficient vector similarity search and clustering — billions of vectors, dozens of index types, CPU and GPU.
Why people choose FAISS
- Industry-standard algorithms, battle-tested at Meta scale
- Unmatched index variety (IVF, HNSW, PQ...)
- GPU acceleration for massive datasets
FAISS at a glance
| Category | Vector database |
| Type | Vector search library |
| License | MIT |
| Runs locally | Yes |
| Built with | C++/Python |
| Skill level | Advanced |
| Best for | raw performance and research-grade control |
Latest releases
Open-source alternatives to FAISS
Other open-source vector database tools worth comparing:
QdrantFast Rust-based vector search
WeaviateVector DB with built-in modules
MilvusBillion-scale vector database
ChromaThe simplest embedding DB for prototyping
pgvectorVector search inside PostgreSQL
LanceDBServerless vector DB for AI
VespaBig-scale hybrid search and ranking platform
pgvectorscaleMake pgvector fast at scale
MarqoVector search with embedding built in
USearchTiny, extremely fast vector indexFAISS head-to-head
FAISS vs QdrantFAISS vs WeaviateFAISS vs MilvusFAISS vs ChromaFAISS vs pgvectorFAISS vs LanceDBFAISS vs VespaFAISS vs pgvectorscaleFAISS vs MarqoFAISS vs USearch
FAQ
Is FAISS free?
FAISS is free and open-source (MIT license), so you can use, self-host and modify it at no cost.
Can I run FAISS locally?
Yes. FAISS is designed to run on your own machine or server, keeping your data private.
What is the best alternative to FAISS?
Popular open-source alternatives include Qdrant, Weaviate, Milvus. See the comparisons above to choose.
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