Open source vector-database projects
Every project in the registry tagged vector-database, ranked by real GitHub adoption.
LlamaIndex is the document processing platform for AI
📑 PageIndex: Document Index for Vectorless, Reasoning-based RAG
Developer-friendly OSS embedded retrieval library for multimodal AI. Search More; Manage Less.
Full-text & vector search at the edge.
Open-source framework for building agentic apps in JavaScript, Go, Dart, and Python, built and used in production by Google
Knowhere extracts, parses, and outputs structured chunks ready for AI Agents and RAG.
The open document intelligence platform for builders and hackers - DMS for the agentic world
Long-term memory for AI assistants. Graph + vector store that recalls decisions, relationships, and context across sessions.
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Frequently asked questions
How many open source vector-database projects are there?
This registry tracks 8 projects tagged vector-database, with 121,967 GitHub stars between them. The most-adopted is llama_index at 52,202 stars.
Are these vector-database projects free to use?
Yes — 7 of the 8 carry an explicit open-source licence across 2 distinct licences, so there is no licence fee. Where a project also sells a hosted or enterprise version, the self-hosted path remains free.
Which vector-database project should I choose?
The list above is ranked by GitHub stars, but stars measure attention rather than fit. Check three things on each card: the licence (permissive versus copyleft), the language it is written in, and the last-push date — a high-star project that has not been pushed in a year is a liability.
Are these vector-database projects still maintained?
8 of the 8 were pushed in the last 90 days, and every card shows its exact last-push date so you can see the rest. Sort your shortlist by that date before committing to a migration.