Faiss vs Milvus
Faiss: Meta's C++/Python library for fast dense-vector similarity search and clustering, CPU and GPU. Milvus: Cloud-native, distributed open-source vector database built for billions of vectors.
key differences
- Milvus is built for larger datasets (Multi-PB) than Faiss (≤ 1 PB).
- Horizontal scaling is manual in Faiss and native in Milvus.
- Only Faiss has in-memory.
- Only Milvus has secondary indexes, full-text search, json, change data capture, ttl / expiry.
choose faiss for
- +Embedding similarity search inside ML pipelines
- +Offline deduplication and clustering
- +Building custom vector search services
- +ANN research and benchmarking
best at · Vector search, Embedded, Scientific
choose milvus for
- +Billion-scale semantic and image search
- +RAG platforms serving many teams
- +Recommendation and deduplication
- +Multimodal retrieval over lakehouse data
best at · Vector search, RAG, Search
Faiss vs Milvus: FAQ
What is the difference between Faiss and Milvus?
Faiss: Meta's C++/Python library for fast dense-vector similarity search and clustering, CPU and GPU. Milvus: Cloud-native, distributed open-source vector database built for billions of vectors. Milvus is built for larger datasets (Multi-PB) than Faiss (≤ 1 PB). Horizontal scaling is manual in Faiss and native in Milvus. Only Faiss has in-memory.
When should I choose Faiss over Milvus?
Choose Faiss for embedding similarity search inside ML pipelines; offline deduplication and clustering; and building custom vector search services. Choose Milvus for billion-scale semantic and image search; RAG platforms serving many teams; and recommendation and deduplication.
Is Faiss or Milvus more popular?
Milvus ranks #35 on the WhichDB Score (45.9/100) and Faiss ranks #40 (44.7/100). Popularity is not fit: check the requirements that matter for your project.
Are Faiss and Milvus open source?
Yes. Faiss is open source. License: MIT License. Yes. Milvus is open source. License: Apache License 2.0.