--- title: "Open-source vector databases for RAG" type: "category" slug: "vector-databases" canonical_url: "https://www.graphcanon.com/categories/vector-databases" tool_count: 149 description: "Compare Qdrant, Chroma, Weaviate, and pgvector for RAG retrieval. GraphCanon ranks open-source vector databases by GitHub adoption and maintenance, not ads." --- # Vector Databases *GraphCanon updated Oct 9, 2026* Vector databases store embeddings for similarity search, the retrieval layer behind most RAG stacks. Use a dedicated store when you need scale, hybrid search, or managed ops; pgvector or an in-memory index often wins below ~100k vectors. GraphCanon ranks tools by live GitHub stars and freshness, then links head-to-head compares and alternatives so you can pick on constraints, not hype. milvus currently leads this list at 46,152 GitHub stars among 149 published tools. 149 tools in this category (showing the top 60 by stars). ## Featured comparisons - [Qdrant vs Chroma](/compare/chroma-core-chroma-vs-qdrant-qdrant.md) - [Qdrant vs Weaviate](/compare/qdrant-qdrant-vs-weaviate-weaviate.md) - [Qdrant vs pgvector](/compare/pgvector-pgvector-vs-qdrant-qdrant.md) ## Alternatives hubs - [Qdrant alternatives](/tools/qdrant-qdrant/alternatives.md) - [Chroma alternatives](/tools/chroma-core-chroma/alternatives.md) - [Weaviate alternatives](/tools/weaviate-weaviate/alternatives.md) ## Stacks - [The RAG stack](/stacks/rag-pipeline.md) ## Tools - [milvus](/tools/milvus-io-milvus.md) - Milvus is a high-performance, cloud-native vector database for scalable vector ANN search (★ 46,152) [Very active] - [TencentDB-Agent-Memory](/tools/tencentcloud-tencentdb-agent-memory.md) - A team-level memory hub for AI Agents, transforming conversations, documents, and code into reusable memory assets. (★ 26,924) [Very active] - [qdrant](/tools/qdrant-qdrant.md) - High-performance, massive-scale Vector Database and Vector Search Engine for AI (★ 34,655) [Very active] - [cognee](/tools/topoteretes-cognee.md) - Cognee is the open-source AI memory platform for agents. (★ 30,850) [Very active] - [meilisearch](/tools/meilisearch-meilisearch.md) - A lightning-fast search engine API bringing AI-powered hybrid search to your sites and applications. (★ 59,345) [Very active] - [redis](/tools/redis-redis.md) - Redis is a preferred cache, data structure server, and document & vector query engine for real-time applications. (★ 76,411) [Very active] - [mempalace](/tools/mempalace-mempalace.md) - The best-benchmarked open-source AI memory system (★ 59,143) [Very active] - [txtai](/tools/neuml-txtai.md) - All-in-one AI framework for semantic search, LLM orchestration and language model workflows (★ 12,959) [Very active] - [weaviate](/tools/weaviate-weaviate.md) - An open-source vector database for vector search and structured filtering (★ 16,819) [Very active] - [WeKnora](/tools/tencent-weknora.md) - Open-source LLM knowledge platform for creating a queryable RAG, autonomous reasoning agent, and self-maintaining Wiki. (★ 19,992) [Very active] - [tidb](/tools/pingcap-tidb.md) - Scalable, cloud-native database with ACID transactions and vector search support. (★ 40,446) [Very active] - [memvid](/tools/memvid-memvid.md) - Memory layer for AI Agents (★ 16,386) [Steady] - [langchain4j](/tools/langchain4j-langchain4j.md) - Java library for building LLM-powered applications on the JVM (★ 13,039) [Very active] - [paradedb](/tools/paradedb-paradedb.md) - One Postgres for application data, full-text search, vector retrieval, and aggregations (★ 9,278) [Very active] - [zvec](/tools/alibaba-zvec.md) - A lightweight, lightning-fast, in-process vector database (★ 15,455) [Very active] - [RuVector](/tools/ruvnet-ruvector.md) - High Performance Real-Time Self-Learning Ai Vector GNN Memory DB (★ 4,502) [Very active] - [OpenMemory](/tools/caviraoss-openmemory.md) - Local persistent memory store for LLM applications (★ 4,510) [Very active] - [chroma](/tools/chroma-core-chroma.md) - Search infrastructure for AI (★ 29,320) [Very active] - [claude-context](/tools/zilliztech-claude-context.md) - Code search MCP for Claude Code. Make entire codebase the context for any coding agent. (★ 12,408) [Steady] - [oceanbase](/tools/oceanbase-oceanbase.md) - The Fastest Distributed Database for Transactional, Analytical, and AI Workloads (★ 10,284) [Very active] - [SocratiCode](/tools/giancarloerra-socraticode.md) - Enterprise-grade codebase intelligence with local setup, hybrid semantic search, and polyglot dependency graphs (★ 3,313) [Very active] - [turbovec](/tools/ryancodrai-turbovec.md) - A vector index built on TurboQuant, written in Rust with Python bindings (★ 14,822) [Very active] - [fastembed](/tools/qdrant-fastembed.md) - Fast, Accurate, Lightweight Python library for creating state-of-the-art embeddings (★ 3,211) [Very active] - [examples](/tools/pinecone-io-examples.md) - Jupyter Notebooks to help you get hands-on with Pinecone vector databases (★ 3,043) [Very active] - [VCPToolBox](/tools/lioensky-vcptoolbox.md) - VCP acts as middleware between AI model APIs and frontend applications for AGI OS development. It enhances LLMs with statefulness, memory, tool invocation capabilities. (★ 2,309) [Very active] - [dragonfly](/tools/dragonflydb-dragonfly.md) - A modern replacement for Redis and Memcached (★ 31,619) [Very active] - [orama](/tools/oramasearch-orama.md) - A complete search engine and RAG pipeline with support for full-text, vector, and hybrid search. (★ 10,557) [Active] - [grepai](/tools/yoanbernabeu-grepai.md) - Semantic Search & Call Graphs for AI Agents (100% Local) (★ 1,878) [Very active] - [memsearch](/tools/zilliztech-memsearch.md) - A persistent, unified memory layer for all your AI agents backed by Markdown and Milvus. (★ 2,627) [Very active] - [infinity](/tools/infiniflow-infinity.md) - AI-native database for LLM applications with fast hybrid search capabilities (★ 4,709) [Active] - [lancedb](/tools/lancedb-lancedb.md) - Developer-friendly OSS embedded retrieval library for multimodal AI (★ 11,456) [Very active] - [databend](/tools/databendlabs-databend.md) - All-in-One Data Warehouse: Analytics, Search, AI, and Python Sandboxing Reimagined From Scratch. (★ 9,444) [Very active] - [selfhost-ai](/tools/kossakovsky-selfhost-ai.md) - Self-hosted AI automation platform (★ 933) [Very active] - [vespa](/tools/vespa-engine-vespa.md) - The AI search platform (★ 7,054) [Very active] - [bootcamp](/tools/milvus-io-bootcamp.md) - Dealing with all unstructured data including reverse image search, audio search, molecular search, video analysis, and question-answer systems. (★ 2,444) [Active] - [Agent_Memory_Techniques](/tools/nirdiamant-agent-memory-techniques.md) - Agent memory for LLMs: runnable Jupyter notebooks on various memory and knowledge techniques. (★ 1,069) [Very active] - [fastembed-rs](/tools/anush008-fastembed-rs.md) - Rust library for generating vector embeddings and reranking locally. (★ 1,016) [Very active] - [SeekStorm](/tools/seekstorm-seekstorm.md) - Vector & Lexical Search Library and Multi-tenancy Server (★ 1,913) [Active] - [OpenSwarm](/tools/unohee-openswarm.md) - Autonomous AI dev team orchestrator powered by Claude Code CLI. (★ 858) [Very active] - [vearch](/tools/vearch-vearch.md) - Distributed vector search for AI-native applications (★ 2,326) [Steady] - [helix-db](/tools/helixdb-helix-db.md) - OLTP graph-vector database built in Rust on Object Storage (★ 5,797) [Very active] - [BambooAI](/tools/pgalko-bambooai.md) - A Python library powered by Language Models (LLMs) for conversational data discovery and analysis. (★ 790) [Very active] - [deeplake](/tools/activeloopai-deeplake.md) - AI Data Runtime for Agents (★ 9,239) [Slowing] - [recipes](/tools/weaviate-recipes.md) - End-to-end notebooks for using Weaviate features and integrations. (★ 947) [Very active] - [NornicDB](/tools/orneryd-nornicdb.md) - Distributed Graph+Vector Database with Temporal MVCC and Low-Latency HNSW Search (★ 881) [Very active] - [langchainrb](/tools/patterns-ai-core-langchainrb.md) - Build LLM-powered applications in Ruby (★ 1,997) [Active] - [cuvs](/tools/nvidia-cuvs.md) - A library for vector search and clustering on the GPU (★ 854) [Very active] - [Wax](/tools/christopherkarani-wax.md) - Single-file memory layer for AI agents with sub-millisecond RAG on Apple Silicon using Metal optimization (★ 799) [Very active] - [JustHireMe](/tools/vasu-devs-justhireme.md) - Local-first AI job intelligence workbench for scraping roles, ranking fit, and generating tailored application materials. (★ 2,249) [Active] - [azure-search-vector-samples](/tools/azure-azure-search-vector-samples.md) - Code samples for vector search capabilities in Azure AI Search (★ 910) [Very active] - [qdrant-client](/tools/qdrant-qdrant-client.md) - Python client for Qdrant vector search engine (★ 1,359) [Very active] - [faraday](/tools/infobyte-faraday.md) - Open Source Vulnerability Management Platform (★ 6,747) [Very active] - [EmbedAnything](/tools/starlightsearch-embedanything.md) - Highly Performant, Modular, Memory Safe and Production-ready Inference, Ingestion and Indexing built in Rust (★ 1,307) [Steady] - [rag_api](/tools/danny-avila-rag-api.md) - ID-based RAG FastAPI: Integration with Langchain and PostgreSQL/pgvector (★ 901) [Steady] - [MineContext](/tools/volcengine-minecontext.md) - Proactive context-aware AI partner (★ 5,518) [Slowing] - [matrixone](/tools/matrixorigin-matrixone.md) - AI-native HTAP database with Git-for-Data and built-in vector search (★ 1,888) [Very active] - [infinispan](/tools/infinispan-infinispan.md) - Highly scalable NoSQL cloud data store and in-memory cache platform (★ 1,352) [Very active] - [RediSearch](/tools/redisearch-redisearch.md) - A query and indexing engine for Redis (★ 6,240) [Very active] - [mcp-server-elasticsearch](/tools/elastic-mcp-server-elasticsearch.md) - Elasticsearch-based MCP server implementation in Rust (★ 718) [Very active] - [SPTAG](/tools/microsoft-sptag.md) - Distributed ANN library for large-scale vector search (★ 5,018) [Very active] ## Common questions ### What are the best vector databases tools? GraphCanon ranks Vector Databases tools by GitHub adoption and freshness. milvus is the current leader (46,152 stars). See the full list on this page - sorted by stars, with [maintenance labels](/glossary/trust-and-signals/maintenance-label) and graph relationships. ### How does GraphCanon rank Vector Databases tools? We sort by GitHub stars and push recency on category pages, not paid placement. Alternatives and compare pages use [typed graph edges](/glossary/knowledge-graph/typed-edge) (alternative, successor, integrates_with) plus shared categories - constraint-first, not marketing votes. ### How many tools are in Vector Databases? 149 published tools are tagged with Vector Databases in the GraphCanon knowledge graph. ### What are popular Vector Databases comparisons? Head-to-head compare pages in this category include Qdrant vs Chroma, Qdrant vs Weaviate, Qdrant vs pgvector. Each comparison uses live GitHub stats and optional [trust signals](/glossary/trust-and-signals/trust-signal) - see the comparisons block on this page. ### Which stacks use Vector Databases? Curated workflow pages that include Vector Databases: [The RAG stack](/stacks/rag-pipeline). Each stack step includes when-not-to-use guidance. ### Where are graph-backed alternatives hubs for Vector Databases? High-intent OSS-vs-OSS alternatives pages include [Qdrant alternatives](/tools/qdrant-qdrant/alternatives), [Chroma alternatives](/tools/chroma-core-chroma/alternatives), [Weaviate alternatives](/tools/weaviate-weaviate/alternatives). Each hub ranks typed graph neighbors and constraint tags - not popularity votes. ### Is there a machine-readable Vector Databases list? Yes. Append `.md` to this URL or fetch [`/md/categories/vector-databases`](/md/categories/vector-databases) for a markdown twin. The JSON API exposes the same corpus at [`/api/graphcanon/categories/vector-databases`](/api/graphcanon/categories/vector-databases). --- **Machine-readable endpoints** - JSON: [`/api/graphcanon/categories/vector-databases`](/api/graphcanon/categories/vector-databases) - LLM index: [/llms.txt](/llms.txt) - Full corpus: [/llms-full.txt](/llms-full.txt) _GraphCanon - The knowledge graph for AI development. https://www.graphcanon.com/_