Overview
Weaviate is an open-source vector database built around putting two kinds of retrieval in one engine. Vector similarity handles meaning, BM25 handles exact keyword hits, and the two can be weighted and fused inside a single query.
It also builds vectorisation into the database itself, so embeddings are produced at write time and there is no separate pipeline to maintain in the application layer.
Key Features
- Hybrid retrieval as the headline: Vector similarity and BM25 keyword search can be combined in one query, which matters when meaning and exact matches are both required, as with model numbers, codes or proper nouns.
- Modular vectorisation: Modules such as text2vec-openai move embedding into the database, so the application only writes raw data and the engine vectorises it.
- Free to self-host: Licensed under BSD-3, so on-premise or private-cloud deployment carries no licence cost, which suits environments where data cannot leave the network.
- Cloud tiers: A 14-day Sandbox trial covers evaluation; Cloud Flex starts at $45/month; Dedicated Cloud starts at $400/month with a 99.95% SLA; enterprise BYOC deployments are available.
- Tunable consistency: Consistency levels can be configured per operation, relaxed for write-heavy batch loads and tightened for real-time traffic, trading throughput against freshness yourself.
Use Cases
- Knowledge bases that need semantic retrieval and exact matching on identifiers or proper nouns
- Fully self-hosted retrieval for organisations where data cannot leave the internal network
- Teams that want to skip building an embedding pipeline and vectorise at write time
- Bulk ingestion jobs that need consistency and throughput tuned per scenario
Pros
- BSD-3 open source with no licence cost to self-host
- Hybrid vector and keyword retrieval works out of the box
- Vectorisation modules are built in, removing a pipeline to maintain
- Clear tiers from cloud trial through paid plans for a smooth upgrade path
Pricing
Free to self-host under BSD-3. Cloud offers a 14-day Sandbox trial; Cloud Flex from $45/month; Dedicated Cloud from $400/month; enterprise BYOC is custom.
Summary
Weaviate stakes its position on hybrid retrieval and self-hosting. It does not chase maximum managed convenience, instead folding both retrieval modes into one engine and bringing vectorisation in as well. That design appeals to regulated industries that are data-sensitive but cannot give up keyword precision. Worth noting: the cloud presence centres on a 14-day Sandbox trial, so for a long-term zero-cost setup, self-hosting is the steadier path.
Version History
- Cloud Flex and Dedicated tiers (2026): Flex from $45/month, Dedicated Cloud from $400/month with a 99.95% SLA