Alternatives to Weaviate for AI Memory in Agent Frameworks
The short answer
Pick the replacement by where your agent’s data already lives. Weaviate is a full vector database with modules, hybrid search and a hosted embeddings service; most agent memory needs less than that: durable storage, per-user filters, updates and deletes. As of November 5, 2026:
- Qdrant — the closest like-for-like swap. Open-source vector server, payload filtering, multi-tenancy, Apache-2.0.
- pgvector — the default if the agent’s app runs on Postgres. Users, sessions and memories live in one database.
- Pinecone — fully managed, nothing to operate, predictable entry price.
- Milvus / Zilliz Cloud — for collections in the hundreds of millions of vectors.
- Chroma — embedded and persistent for prototypes and single-process agents.
- Mem0 or Zep — a memory layer that decides what to remember; it runs on top of one of the stores above.
The comparison
| Type | Licence / latest | Managed entry price (Nov 5, 2026) | Free managed tier | Best for | |
|---|---|---|---|---|---|
| Weaviate (baseline) | Vector DB + modules | BSD-3-Clause or Weaviate License · v1.39.15 (Nov 4) | Flex from $45/mo; Premium from $400/mo | 100,000 objects, 1 GB memory, 10 GB disk | Hybrid search + hosted embeddings |
| Qdrant | Vector DB | Apache-2.0 · v1.20.0 (Oct 22) | Standard: usage-based (vCPU, memory, disk) | 0.5 vCPU, 1 GB RAM, 4 GB disk | Self-hosted or managed server for many agents |
| pgvector | Postgres extension | PostgreSQL licence · v0.8.7 | Your Postgres bill | — | Apps already on Postgres |
| Pinecone | Managed vector DB | Closed | Builder $20/mo flat; Standard $50/mo minimum | Starter (free) | Zero operations |
| Milvus / Zilliz Cloud | Vector DB | Apache-2.0 · v3.0.5 (Oct 30) | Serverless from $0; Dedicated from $126/mo | 5 GB storage, up to 5 collections | Very large collections |
| Chroma | Embedded / cloud DB | Apache-2.0 | Usage only: $2.50/GiB written, $0.33/GiB-month | $5 credits for new users | Prototypes, single-process agents |
Versions are each project’s latest GitHub release; prices from each vendor’s pricing page on November 5, 2026.
When each alternative wins
Qdrant — when you want Weaviate’s shape without Weaviate. Qdrant is a standalone vector server with JSON payload filtering, which is how agent memory scopes recall to one user, session or time window. It supports multi-tenancy inside one collection, so thousands of users do not need thousands of collections. The managed Standard tier bills by vCPU, memory and disk per hour with a 99.5% uptime SLA; Premium adds SSO, private VPC links and a 99.9% SLA for a minimum spend. Migration from Weaviate is mostly a re-index: export objects and vectors, recreate the schema as payload fields.
pgvector — when memory belongs next to your users table. An agent that already stores users, conversations and permissions in Postgres gets the simplest architecture by adding a vector column: WHERE user_id = $1 ORDER BY embedding <=> $2 LIMIT 10. Transactions, row-level security and backups come with the database. It is the cheapest option and the easiest to delete a user from, which matters for GDPR requests. It is not the fastest at tens of millions of vectors per tenant; add HNSW indexes and partition by tenant before you get there.
Pinecone — when nobody wants to run a database. Builder is $20 a month flat for solo developers and small teams, with multiple projects and a choice of cloud and region; Standard has a $50 monthly minimum and adds Dedicated Read Nodes, backup and restore, RBAC and SSO; Enterprise has a $500 minimum and a 99.95% uptime SLA. Bring-your-own-cloud runs Pinecone in your own account. Use namespaces per user or per agent for memory isolation.
Milvus and Zilliz Cloud — when the memory is huge. Milvus 3.0.5 (October 30, 2026) is built for very large collections, and Zilliz Cloud’s dedicated clusters scale to 2,048 compute units. Zilliz lists capacity-optimised units at about 8 million 768-dimension vectors per CU from $16 per million vectors a month, and tiered-storage units at about 40 million per CU from $5. That scale is rarely needed for one assistant, but it is for a platform that stores memory for millions of end users.
Chroma — when you are still prototyping. Chroma runs in-process, persists to disk and supports metadata filters, so an agent’s memory survives restarts with no server. Chroma Cloud is purely usage-based: $2.50 per logical GiB written, $0.33 per GiB-month stored, and reads at $0.0075 per TiB queried plus $0.09 per GiB returned. Forking a collection costs $0.03, which is handy for testing a memory schema change.
Do you need a memory layer instead?
A vector database stores what you give it. A memory layer decides what to store: it extracts facts and preferences from conversations, merges duplicates and expires outdated facts.
- Mem0 changed its pricing in late October 2026. The Free plan covers unlimited end users, 10,000 adds and 1,000 retrievals a month for the first 30 days with model calls paid by Mem0, then 50,000 adds and 10,000 retrievals a month if you connect your own LLM key. Graph memory, user profiles and the “Dream” consolidation are on Custom plans. Its open-source core runs on Qdrant, pgvector or Chroma.
- Zep builds a temporal knowledge graph of users and conversations. Flex costs $125 a month for 50,000 credits, then $25 per 10,000 credits, at 600 requests a minute.
For the full memory-layer ranking see best AI agent memory systems; if you are leaving a library rather than a database, see alternatives to FAISS for AI agent memory.
How to choose in three questions
- Is your app on Postgres? Yes: pgvector. Stop here unless you expect more than ~10 million vectors per tenant.
- Will you run infrastructure? No: Pinecone (or Zilliz Cloud at very large scale). Yes: Qdrant.
- Do you need extraction and consolidation, not just recall? Add Mem0 or Zep on top of the store you picked.
Embedding calls are a running cost on top of storage; at agent scale they often cost more than the database. Price them against current API prices. For a wider look at stores, see best vector databases.
Last verified: November 5, 2026. Versions from each project’s GitHub releases; prices from the Weaviate, Qdrant, Pinecone, Zilliz, Chroma, Mem0 and Zep pricing pages.