Weaviate vs 
pgvector
Weaviate vs pgvector compared for 2026 — features, license, ease of use, performance and which one to choose. Vector DB with built-in modules vs Vector search inside PostgreSQL.
Updated regularly · curated by OpenSourceAI.tech
Weaviate vs pgvector at a glance
| Spec | Weaviate | pgvector |
|---|---|---|
| Category | Vector database | Vector database |
| Type | Vector database | Postgres extension |
| License | BSD-3-Clause | PostgreSQL |
| Runs locally | Self-hosted | Self-hosted |
| Primary language | Go | C |
| Ease of use | Intermediate | Beginner |
| Best for | teams wanting hybrid search and built-in modules | teams already running PostgreSQL |
| GitHub stars | 16.7k | — |
Feature comparison
| Feature | Weaviate | pgvector |
|---|---|---|
| Self-hostable | ✓ | ✓ |
| Managed cloud | ✓ | ✓ |
| Metadata filtering | ✓ | ✓ |
| Hybrid search | ✓ | ✓ |
| Horizontal scaling | ✓ | ✓ |
| REST API | ✓ | ✗ |
How Weaviate and pgvector score
| Criterion | Weaviate | pgvector |
|---|---|---|
| Popularity | 3.5 | n/a |
| Maintenance | 5.0 | n/a |
| Ease of use | 3.5 | 5.0 |
| Privacy | 4.5 | 4.5 |
| License freedom | 5.0 | 5.0 |
Scores are computed automatically from public signals — GitHub stars (popularity), recent commit activity (maintenance), license type (freedom), local-first design (privacy) and onboarding complexity (ease of use). Indicative, not a verdict.
What each one is
Weaviate
Weaviate is an open-source vector database with built-in vectorization modules, hybrid search and a GraphQL API for AI-native applications.
- Built-in vectorization and reranker modules
- Hybrid (vector + keyword) search
- GraphQL and REST APIs
pgvector
pgvector is a PostgreSQL extension that adds vector similarity search to your existing database, so you can do RAG without a separate vector store.
- No new infrastructure — it is just Postgres
- Keep vectors next to relational data
- Mature, well-supported ecosystem
Key differences
Weaviate is vector database, while pgvector is postgres extension. Their licenses differ (BSD-3-Clause vs PostgreSQL), which matters if you ship a commercial product. Weaviate leans more intermediate-friendly, whereas pgvector is more suited to beginner users. In short, Weaviate fits teams wanting hybrid search and built-in modules, and pgvector fits teams already running PostgreSQL.
Which should you choose?
Choose Weaviate for teams wanting hybrid search and built-in modules. Choose pgvector for teams already running PostgreSQL.
There is rarely one winner — many setups use both. The right pick depends on your hardware, your team's skills, and whether you value simplicity or control.
Frequently asked questions
Is Weaviate or pgvector easier to use?
pgvector is generally the easier of the two to get started with, while Weaviate rewards more setup with more control.
Are Weaviate and pgvector free?
Weaviate is free and open source (BSD-3-Clause), and pgvector is free and open source (PostgreSQL). Neither charges for the core software.
Can I run Weaviate and pgvector locally?
Weaviate: self-hosted · pgvector: self-hosted. Both can be used without sending your data to a third-party cloud where their setup allows.
Weaviate vs pgvector — which should I pick in 2026?
Choose Weaviate for teams wanting hybrid search and built-in modules. Choose pgvector for teams already running PostgreSQL.
People also compare
Explore more open-source AI
Browse thousands of open-source AI tools, models and projects — all curated in one place, updated daily.
Explore the directory →