Chroma

Chroma is an open-source embedding database focused on developer experience, letting you add retrieval to LLM apps with minimal setup. It runs embedded or self-hosted for free and offers a serverless Chroma Cloud billed purely on usage. It is especially popular for prototyping RAG and local workflows.

Chroma is an open-source embedding database built to make retrieval simple for developers. Its defining trait is ergonomics: you can run it in-process with a few lines of Python or JavaScript, store documents and their embeddings, and query by similarity without standing up any infrastructure. This makes it a favorite for prototyping RAG and for local and notebook workflows, while still scaling into server deployments. Chroma handles embedding, storage, and querying with a clean API, integrates natively with LangChain and LlamaIndex, and can call embedding providers or use local models. It is fully open source under Apache 2.0 and free to self-host, whether embedded, single-node, or in its distributed configuration. The project's emphasis is on developer experience and getting from idea to working retrieval quickly. Chroma Cloud, a fully managed serverless offering backed by a Rust engine on object storage, reached general availability in August 2025. It bills purely on usage (writes, storage, queries) with no always-on cluster fee, which the company argues makes it substantially cheaper than provisioned managed databases for many workloads. Chroma competes with Pinecone, Weaviate, Qdrant, and Milvus, differentiating on simplicity and a serverless cost model.