pgvector vs Weaviate

Pick two tools from the same category to compare side-by-side.

	pgvector Postgres extension for vector similarity search.	Weaviate Open-source, cloud-native vector database in Go that stores both objects and vectors.
Category	retrieval	retrieval
Vendor type	open source	hybrid
Pricing	free	freemium
Strengths	+ Use the database you already run + Open source + Transactional consistency with relational data	+ Hybrid vector plus BM25 keyword search in a single query API + Built-in vectorizer integrations generate embeddings at ingest time + Multi-tenancy designed for tens of thousands of tenants + Enterprise features including RBAC, SOC 2, and HIPAA compliance options
Tradeoffs	− Single-machine scaling limits vs purpose-built vector DBs	− HNSW indexes are memory-hungry, driving up infrastructure cost at large scale − Collection/schema and module configuration adds setup complexity versus simpler stores − Expanding product surface (agents, embeddings, memory) increases the learning surface beyond core vector search
Used in stacks	4	0