head to head · open source
faiss vs zvec
faiss has 41,256 GitHub stars, 4,586 forks, 327 open issues and last shipped 2 days ago. zvec has 16,181 stars, 1,017 forks, 56 open issues and last shipped 2 days ago. faiss leads on adoption by 155% (41,256 vs 16,181 stars). faiss is written in C++ under MIT; zvec is written in C++ under Apache-2.0. faiss has attracted 11% as many forks as stars, zvec 6%. faiss was the more recently maintained of the two, and both are self-hostable with no licence fee.
Two open source projects, one decision. Both are free and self-hostable — the differences are community size, license terms, language stack and release pace.
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Side by side
| faiss | zvec | |
|---|---|---|
| GitHub stars | ★ 41K | ★ 16K |
| License | MIT | Apache-2.0 |
| Written in | C++ | C++ |
| Last push | 2026-11-03 | 2026-11-03 |
| Forks | ⑂ 4.6K | ⑂ 1.0K |
| Self-hosting | Yes | Yes |
| Data ownership | Your server | Your server |
pick faiss if
- You weight community size — 41K stars and counting
- You want the MIT license terms
- Your stack matches C++
- You value the larger contributor base for long-term maintenance
pick zvec if
- You want the zvec feature set and don't need the biggest community
- You prefer the Apache-2.0 license terms
- Your stack matches C++
- You evaluated both and zvec fits your workflow better
About faiss
Faiss Faiss is a library for efficient similarity search and clustering of dense vectors. It contains algorithms that search in sets of vectors of any size, up to ones that possibly do not fit in RAM. It also contains supporting code for evaluation and parameter tuning. Faiss is written in C++ with complete wrappers for Python/numpy. Some of the most useful algorithms are implemented on the GPU. It is developed primarily at Meta's Fundamental AI Research group. News See CHANGELOG.md for detailed information about latest features. Introduction Faiss contains several methods for similarity search. It assumes that…
read the full faiss overview →
About zvec
English 中文 🚀 Quickstart 🏠 Home 📚 Docs 📊 Benchmarks 🔎 DeepWiki 🎮 Discord 🐦 X (Twitter) Zvec is an open source, in process vector database — lightweight, lightning fast, and designed to embed directly into applications. Battle tested within Alibaba Group, it delivers production grade, low latency and scalable similarity search with minimal setup. [!Important] 🚀 v0.7.0 (August 24, 2026) zvec grep ( zg ) : Local first workspace search that unifies ripgrep, BM25, and vector search behind one CLI — built for humans and AI agents. ReMe integration : zvec is now a file store backend in ReMe, the memory…
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Frequently asked questions
Is faiss or zvec more popular?
faiss has 41,256 GitHub stars and zvec has 16,181. faiss has the larger community by that measure.
Are faiss and zvec free?
Both are open source. faiss is licensed under MIT and zvec under Apache-2.0. Neither carries a licence fee.
What is the difference between faiss and zvec?
faiss is written in C++ and zvec in C++. The practical differences are community size, licence terms, language stack and release cadence — all compared in the table above.
Which should I choose, faiss or zvec?
Choose faiss if you want the larger community (41,256 stars) or its MIT licence terms. Choose zvec if its feature set, stack or Apache-2.0 licence fits better. Both are self-hostable.