Weaviate
activeby Weaviate B.V. · since 2019
Open-source AI-native vector database with hybrid search, modules for embeddings and multi-tenancy.
Overview
Weaviate is an open-source vector database written in Go that stores objects and their vectors together, with BM25 and hybrid search, filtering, multi-tenancy and pluggable vectorizer and generative modules that call OpenAI, Cohere, Hugging Face and others for you. It shards and replicates natively, offers tunable consistency, and supports PQ, BQ and rotational quantization to fit large indexes in memory. The core is BSD-3-Clause, while some enterprise features are now in a separately licensed directory. Weaviate Cloud provides shared (Flex) and dedicated (Premium) managed clusters.
Strengths & trade-offs
Strengths
- +Hybrid BM25 plus vector search with fusion options in one query
- +Vectorizer and generative modules remove glue code for embeddings and RAG
- +Native multi-tenancy with tenant offloading to cold storage
- +Quantization (PQ/BQ/RQ) cuts memory for large indexes
- +Open-source core with a straightforward managed cloud
Trade-offs
- −Memory-hungry HNSW unless you tune quantization
- −GraphQL-era API surface has been reworked several times
- −Enterprise features moving to a separate license
- −No joins or relational modeling
Great for
- +RAG over documents with hybrid retrieval
- +Multi-tenant SaaS semantic search
- +Product and content recommendation
- +Agent memory stores
Think twice for
- −Transactional workloads
- −Analytics and aggregations
- −Tiny embedded apps (use sqlite-vec or LanceDB)
Capabilities
Native or official first-party support · 8 of 25 tracked
Scale & consistency
- Comfortable data size
- Large · ≤ 1 PB
- Horizontal scaling
- Native
- Multi-region
- No
- Transactions
- None
- Consistency
- Tunable, Eventual
- Schema
- Flexible
- Architecture
- Distributed, Client server
- Query languages
- GraphQL, Weaviate query API
Sharding and Raft-based schema replication across nodes; tenants can be offloaded to object storage.
Deployment
available on · AWS · Google Cloud · Azure
Ecosystem
Alternatives to Weaviate
Rust vector search engine with rich payload filtering, quantization and a managed cloud.
weaviate vs qdrant →Cloud-native, distributed open-source vector database built for billions of vectors.
weaviate vs milvus →Fully managed serverless vector database with built-in embedding, reranking and assistants.
weaviate vs pinecone →Open-source retrieval database for AI apps, from embedded Python to serverless Chroma Cloud.
weaviate vs chroma →Big-data serving engine for search, recommendation and RAG with tensors and ML ranking.
weaviate vs vespa →Lucene-based distributed search and analytics engine for text, vectors, logs and metrics.
weaviate vs elasticsearch →Weaviate FAQ
What is Weaviate?
Weaviate is a vector database by Weaviate B.V., first released in 2019. Weaviate is an open-source vector database written in Go that stores objects and their vectors together, with BM25 and hybrid search, filtering, multi-tenancy and pluggable vectorizer and generative modules that call OpenAI, Cohere, Hugging Face and others for you. It shards and replicates natively, offers tunable consistency, and supports PQ, BQ and rotational quantization to fit large indexes in memory. The core is BSD-3-Clause, while some enterprise features are now in a separately licensed directory. Weaviate Cloud provides shared (Flex) and dedicated (Premium) managed clusters.
Is Weaviate open source?
Yes. Weaviate is open source. License: BSD-3-Clause (core); enterprise features under the Weaviate License.
Does Weaviate support ACID transactions?
No. Weaviate does not provide ACID transactions; its consistency model is tunable, eventual.
Does Weaviate scale horizontally?
Weaviate scales horizontally out of the box, with built-in sharding or partitioning. It is comfortable at large scale (≤ 1 PB).
How can I run Weaviate?
You can self-host it and use the vendor's managed cloud. Managed offerings include Weaviate Cloud. It is available on AWS, Google Cloud and Azure.
What is Weaviate best for?
Weaviate is a strong fit for RAG over documents with hybrid retrieval; multi-tenant SaaS semantic search; and product and content recommendation. Think twice for transactional workloads.
What are the best alternatives to Weaviate?
Common alternatives to Weaviate include Qdrant, Milvus, Pinecone, Chroma and Vespa. The right choice depends on your workload, scale and hosting; WhichDB's smart match ranks them against your requirements.
How popular is Weaviate?
Weaviate ranks #65 of 844 databases on the WhichDB Score (33.4/100), and #6 among vector databases. The score combines public adoption signals such as package downloads, GitHub activity, job posts and developer discussion.