Pinecone

Pinecone is a managed vector database purpose-built for semantic search and retrieval-augmented generation. You send embeddings from any model and query them by similarity, with hybrid sparse-dense scoring, metadata filtering, namespaces for multi-tenant isolation, and serverless indexes that scale without capacity planning. It handles the indexing, sharding, and replication work that would otherwise be bespoke engineering.

The API-first service plugs into OpenAI, Hugging Face, and LangChain pipelines, and the free Starter tier is enough for prototypes and small projects. Serverless pricing tracks storage, reads, and writes rather than provisioned nodes, and recent releases add integrated embedding inference and reranking that trim glue code. It suits engineering teams shipping RAG assistants, recommendation features, or deduplication at serious scale; teams with tiny datasets or strict residency demands may find a local open-source index simpler and cheaper.