What problem does it solve?
FAISS provides fast and scalable similarity search for dense vector embeddings, removing the bottleneck of slow nearest-neighbor queries on large embedding collections so you can retrieve relevant items with low latency.
Core Features & Use Cases
- Exact and Approximate k-NN: Supports exact Flat indices and approximate indices like IVF, HNSW, and PQ for trade-offs between speed, memory, and accuracy.
- GPU Acceleration & Scaling: Move indices to single or multiple GPUs for 10-100× speedups on large datasets and use IVF+PQ for billion-scale storage efficiency.
- Integrations & Workflows: Commonly used for embedding-based retrieval, recommendation systems, semantic search, and as a vector store backend with LangChain or LlamaIndex.
- Use Case Example: Build an IVF+PQ index for 100 million document embeddings, tune nprobe and PQ hyperparameters for desired recall/latency, save the trained index, and serve nearest-neighbor search queries.
Quick Start
Create a FAISS index for your embeddings (choose Flat/IVF/HNSW/PQ), train if required, add your vectors, and run a k-NN search for the top 5 results.