Name Open Source License GitHub stars  Developed in (language) Summary Business Model Embeds / Uses founding date / first released date In-memory Unterstützung Sharding Index Types Consistency Model Benchmarks (Performance?) Approximate Nearest Neighbor (ANN) Vector Databases Funding Who's behind it HQ in 
Chroma Y Apache-2.0 4.4k ⭐ Python & Typescript Chroma is a Commercial Open Source vector database Preparing a (Partly Open) SaaS model* [Commercial Open Source] HNSW lib, DuckDB; based on ClickHouse looks like 2022 N Dynamic segment placement       Y 20.3M USD, seed Chroma Inc. 🇺🇸
Marqo AI Y Apache-2.0 2.8k ⭐ Python A tensor-based cloud-native commercial Open Source search and analytics engine. Open SaaS Tensor-based   Y HNSW   -   undisclosed preseed in May 2022 S2Search Australia Pty Ltd 🇦🇺
Milvus Y Apache-2.0 18k ⭐ GoLang & Python Milvus is a cloud-native Commercial Open Source vector database (Partly Open) SaaS* [Commercial Open Source] Initial blog post from them said SQLite, but meanwhile they said RocksDB - exchanged?
they also have a ChatGPT-Cache that is build on SQLite
and say "Milvus uses SQLite or MySQL to manage metadata"
founded 2017, first released: 2019 N Dynamic segment placement ANNOY; HNSW; IVF_PQ; IVF_SQ(; IVF_FLAT; FLAT; IVF_SQ8_H; RNSG Strong, bounded staleness, session, and eventually. The default consistency level in Milvus is bounded staleness.  not comparative Y 113M USD, series B Zilliz 🇺🇸
ObjectBox Y Apache-2.0   C++, supports native language APIs in Java, Flutter / Dart, Swift, Python, GoLang, and C++ ObjectBox is an on-device vector database for Edge AI on Mobile, IoT, Embedded and other commodity devices Open Source

Paid feature: Data Sync
HNSW built and optimized from scratch for efficiency / speed on devices with limited resources development of the initial on-device database started in 2015; released the vector search to become the first on-device vector database for productive use early in 2024 Y N HNSW Transactionally safe, ACID   Y Seed in 2018 ObjectBox 🇪🇺
Pinecone
N Proprietary NA   Pinecone is a fully managed vector database that specializes in enabling semantic search capabilities SaaS built on top of Faiss first released in 2019 N Y proprietary Eventual Consistency more programming language comparison for vector databases Y (proprietary), plus KNN (with Faiss) 138M, series B Pinecone Systems Inc 🇺🇸
Qdrant Y Apache-2.0 6.6k ⭐ Rust Qdrant is a Commercial Open Source vector similarity search engine and vector database Open SaaS RocksDB first released: 2021 Y Y, static sharding HNSW (SQ & PQ) Eventual Consistency, tunable consistency compares to weaviate, milvus, elastic (note: redis took too long to complete) Y 9.8M € Qdrant Solutions GmbH 🇪🇺
Vald Y Apache-2.0 1.2k ⭐ GoLang Vald is a cloud-native Open Source distributed approximate nearest neighbor (ANN) dense vector search engine Community project, currently looks like no commercial interests are pursued uses the vector search engine NGT Technology incubation at Yahoo! Japan Corporation, development was stared in 2019 N/A N/A N/A not comparitive, but Vald performance only Y (NGT) - Yusuke Kato (Yahoo Japan Corporation), Kiichiro Yukawa (Yahoo Japan Corporation) 🇯🇵
Vespa Y Apache-2.0 4.4k ⭐ Java & C++ Vespa is a Commercial Open Source vector database by Yahoo! It is a search engine which supports vector search, lexical search, and search in structured data Open SaaS Originally a web search engine (alltheweb), acquired by Yahoo! in 2003 and later open sourced as Vespa in 2017; sinde Oct 2023 spinoff, raised series A in Nov 2023 maintains disk and memory structures for documents Y Custom HNSW (Multi-vector hybrid HNSW-IF) Eventual Consistency not comparative  Y Spinoff from Yahoo! in Oct 2023, then raised a 31M USD series A Yahoo! 🇺🇸
Weaviate Y BSD 5.6k ⭐ Assembly, C++, GoLang Weaviate is a commercial Open Source cloud-native vector database that stores both objects and vectors. Open SaaS started in 2018 as a traditional graph database, first released in 2019 N Y, static sharding a custom HNSW PQ algorithm that supports CRUD Eventual Consistency not comparative, just evaluating their own performance  Y (multiple ANN algorithms as long as they support full CRUD) 67.7M USD, series B SeMI Technologies 🇪🇺