What Is a Vector Database?
A vector database is a database built to store and search
high-dimensional vectors called embeddings — numerical representations of text, images,
audio, or other data produced by AI models. Instead of matching exact keywords, it finds the items
whose embeddings are nearest in meaning to a query, using
approximate nearest-neighbour (ANN) search across millions or billions of vectors in milliseconds.
That makes vector databases the memory and retrieval layer
of modern AI — the engine behind retrieval-augmented generation (RAG), semantic search,
recommendation, and long-term memory for
AI agents. They let applications ground
large language models in private,
up-to-date data. This guide covers the specialist companies that build them; for the models and
compute on either side of this layer, see our
LLM companies and
AI infrastructure guides.
Vector Database Companies — Detailed Reviews
Ordered roughly by market presence: the leading managed option first (Pinecone), then the major
open-source projects and their commercial backers, and finally the internet-scale serving engine.
1. Pinecone
New York, USA · Founded 2019 · Managed vector database
Serverless
Managed
$750M
Valuation (Series B)
20,000+
Organisations served
Pinecone is the company that popularised the managed vector database and remains the best-known
commercial name in the category. Founded in 2019 by
Edo Liberty — former director of research at AWS and
head of Amazon AI Labs — and headquartered in New York City, Pinecone pioneered the fully
managed, serverless vector database: developers send
embeddings and queries through a simple API while Pinecone handles indexing, scaling, and
low-latency search behind the scenes.
Its 2024 serverless re-architecture decoupled storage from compute to cut costs at scale, and the
platform now serves more than 20,000 organisations. Pinecone has raised about $138 million,
including a $100 million Series B led by Andreessen Horowitz
at a $750 million valuation, with Menlo Ventures, ICONIQ Growth, and Wing Venture Capital. Choose
Pinecone when you want a production-ready, fully managed vector database with minimal operational
overhead — the path of least resistance for teams that would rather ship than run infrastructure.
2. Zilliz (Milvus)
Redwood City, USA · Founded 2017 · Open source + managed cloud
Milvus
Open source
10,000+
Enterprise deployments
Billion
Scale vector search
Zilliz is the company behind Milvus, the most widely
deployed open-source vector database in the world. Founded in 2017 by Charles Xie and now
headquartered in Redwood City, California, Zilliz built Milvus as a purpose-built, cloud-native
engine for billion-scale vector search and donated it to
the LF AI & Data Foundation, where it has grown past 40,000 GitHub stars and powers more than
10,000 enterprise deployments — including NVIDIA, Salesforce, eBay, Airbnb, and DoorDash.
The 2025 Milvus 2.5 release added native hybrid search,
unifying lexical and semantic retrieval in a single engine, and the company commercialises the
project through the fully managed Zilliz Cloud. Zilliz has raised roughly $113 million, including
a Series B extension led by Prosperity7 Ventures, with Temasek's Pavilion Capital and Hillhouse
among its backers. Choose Zilliz/Milvus when you want open-source flexibility, no per-vector
vendor pricing, and battle-tested performance at the very largest scales.
3. Weaviate
Amsterdam, Netherlands · Founded 2019 · Open source + managed cloud
AI-native
Open source
Hybrid
Keyword + vector search
Modules
Built-in model integration
Battery
Series C lead (+ Index)
Weaviate is an open-source, AI-native vector database
designed to make building search and generative AI applications straightforward. Founded in 2019
by Bob van Luijt and headquartered in Amsterdam, Weaviate combines vector search with structured
filtering and built-in modules that connect directly to
embedding and generative models, so teams can run hybrid (keyword plus vector) search and
retrieval-augmented generation without stitching together multiple systems.
It is available as open-source software and as the managed Weaviate Cloud. In October 2025 the
company raised a $50 million Series C led by Battery
Ventures and Index Ventures, with New Enterprise Associates, building on its earlier $50 million
Series B. Weaviate has become a favourite of developers who want an open, model-integrated
database with a strong developer experience. Choose Weaviate when you want open-source ownership
plus native model integration and hybrid search out of the box.
4. Qdrant
Berlin, Germany · Founded 2021 · Open source + managed cloud
Rust
Open source
Qdrant is a high-performance, open-source vector database and search engine written in
Rust, built for speed, memory efficiency, and production
reliability. Founded in 2021 by Andrey Vasnetsov and Andre Zayarni and headquartered in Berlin,
Qdrant has become one of the fastest-growing open-source projects in the category, surpassing 250
million downloads and 29,000 GitHub stars, with production users including Tripadvisor, HubSpot,
OpenTable, Bazaarvoice, and Bosch.
Its Rust core gives it strong price-to-performance, and features such as
quantization and on-disk storage keep memory costs low at
scale; the company is positioning around "composable" vector search as core production
infrastructure. In March 2026 Qdrant raised a $50 million Series B led by AVP, with Bosch Ventures,
Spark Capital, Unusual Ventures, and 42CAP, bringing total funding to about $87.8 million. Choose
Qdrant when raw performance, cost efficiency, and self-hosting control matter most.
5. Chroma
San Francisco, USA · Founded 2022 · Open source + managed cloud
Developer-first
Open source
LangChain
Ecosystem default
Chroma is the open-source, developer-first embedding database
that became the default starting point for building LLM applications. Founded in 2022 by Jeff Huber
and Anton Troynikov and headquartered in San Francisco, Chroma is designed to make knowledge and
memory pluggable for AI apps: a few lines of Python or JavaScript give developers embeddings
storage, vector search, full-text search, metadata filtering, and multi-modal retrieval, with a
lightweight local mode for prototyping that scales to a hosted cloud.
Its tight fit with the LangChain and LlamaIndex
ecosystems made it ubiquitous in early RAG tutorials and prototypes. Chroma has raised about $20.3
million, led by an $18 million seed round from Quiet Capital with angels including Naval Ravikant,
Jack and Max Altman, and Vercel's Guillermo Rauch, at a $75 million valuation. Choose Chroma when
developer experience and fast prototyping are the priority and you want a frictionless path from
local experiment to production.
6. Vespa.ai
Trondheim, Norway · Yahoo spin-out (2023) · Open source + managed cloud
Serving engine
Open source
20+ yrs
Built inside Yahoo
Unified
Vector + text + tensors
Vespa.ai is a battle-tested big-data serving engine that
combines vector search, tensor computation, lexical search, and structured filtering in a single
platform built for very large scale. It was developed inside Yahoo more than two decades ago to
power search, recommendations, and personalisation across billions of documents in real time, and
spun out as an independent company in 2023.
Headquartered in Trondheim, Norway, Vespa targets the most demanding production workloads —
retrieval-augmented generation, recommendation, ad targeting, and hybrid search where latency and
scale are critical — applying machine-learned ranking to
data at serving time. In November 2023 the company raised a $31 million Series A led by Blossom
Capital. Choose Vespa when you need a single engine that unifies vector, text, and structured
retrieval with sophisticated ranking at internet scale, rather than a vector store bolted onto a
separate search system.
Managed vs. Open Source — and the Incumbents Adding Vector Search
The clearest way to compare these companies is by deployment model. At one end,
Pinecone is fully managed and serverless — you never touch
infrastructure, and you pay for the convenience. At the other, the
open-source leaders — Milvus (Zilliz), Weaviate, Qdrant,
Chroma, and Vespa — let you self-host for control, cost predictability, and data sovereignty, while
each also offers a managed cloud for teams that want the best of both. Among them the emphasis
differs: Milvus for billion-scale maturity, Weaviate for model-integrated AI-native features, Qdrant
for Rust-powered performance and cost, Chroma for developer experience, and Vespa for unified search
at internet scale.
It is also worth knowing that the specialists are not the only option. Established databases have
added vector search — pgvector on PostgreSQL, plus vector
capabilities in Redis, MongoDB Atlas, and Elasticsearch — and for smaller workloads that can be
enough to avoid adding a new system. The dedicated vector databases on this page earn their place
when scale (tens of millions to billions of vectors), latency under load, advanced filtering, or
features like quantization and distributed indexing become the bottleneck. A common pattern is to
start on pgvector and graduate to a specialist as the workload grows.
Reality Check: What a Vector Database Will and Won't Fix
A vector database is essential plumbing for RAG and semantic search, but it is not a silver bullet.
Retrieval quality depends far more on your embedding model,
chunking strategy, and ranking than on which database you pick — a great database returning
poorly chosen chunks still produces poor answers. For many early-stage projects, a vector extension
on an existing database (pgvector, Redis, MongoDB Atlas, Elasticsearch) is enough, and adding a
dedicated system too early is a common source of needless complexity.
The category is also young and consolidating: the
specialists are smaller and earlier-stage than the foundation-model and infrastructure giants they
serve, and incumbents bundling vector search apply real competitive pressure. The durable winners
will be those that lead on hybrid search, cost efficiency at scale, and developer experience — not
just raw nearest-neighbour speed. Treat proven production deployments and a healthy
open-source community as better signals than benchmark charts or headline funding.