Pinecone
Managed-only, zero-ops, strong metadata support. Exceptional query speed and low latency. 2026 shift from per-pod to serverless pricing — favorable for low-volume, risky for high-query enterprise workloads.
Qdrant
Agent-native retrieval features — relevance feedback (1.17), tiered multitenancy, low-latency filtered search (4ms p50). Self-hosted or cloud. The performance leader for agent memory backends in 2026.
Weaviate
Best-in-class native hybrid search (vector + BM25 without plugins). Multi-modal support. Flexible setup options. Winner when your use case requires blended keyword + semantic retrieval.
Practitioner Heuristic
Operational simplicity matters most? Pinecone. Raw performance at scale? Qdrant. Native hybrid search? Weaviate. Budget-constrained Postgres shop? pgvector. Billion-scale? Milvus. Don’t overthink — most orgs never outgrow option #1.