Vector databases
RAG, semantic search and agent memory all come down to one query: find the nearest vectors, fast, with filters. Pinecone is managed only. Qdrant, Weaviate and Chroma are open source with a cloud on top. Glider keeps every write in your own S3 bucket. KiviDB adds vector search to a Redis-compatible store. 6 tools, in the order they appear in the directory. This is not a ranking.
Grouped by job: AI Agent Infrastructure
Glider
Open-source single-node vector database in Rust that makes every acknowledged write durable in S3-compatible storage, with filtered nearest-neighbor search over an HTTP API, a Python client and an MCP memory server for agents.
KiviDB
Open-source (AGPL-3.0), multi-threaded Redis and Valkey alternative written in Rust that speaks RESP2/RESP3, so existing Redis clients work unchanged, with full-text and vector search built in; self-host it or use KiviDB Cloud.
Pinecone
Fully managed vector database: serverless dense, sparse and full-text indexes on AWS, GCP or Azure, with hosted embedding and reranking models, Pinecone Assistant for chat and agent apps, and bring-your-own-cloud on Enterprise. Free Starter plan.
Qdrant
Open-source (Apache-2.0) vector database and search engine written in Rust: filtered vector search you can self-host, or run on Qdrant Cloud on AWS, GCP or Azure with a free 1 GB cluster, usage-based dedicated clusters, and hybrid or private cloud on your own infrastructure.
Weaviate
Open-source (BSD-3-Clause) vector database that stores objects and vectors together, with hybrid search, filtering, multi-tenancy and vector compression. Self-host it or use Weaviate Cloud, which adds hosted embeddings and a Query Agent; free cluster for 100,000 objects.
Chroma
Open-source (Apache-2.0) search infrastructure for AI: vector, full-text and metadata search. Self-host it or use serverless Chroma Cloud, billed per GiB written, stored and queried, with free credits to start.
Open source, where it runs, what it costs.
Straight from each vendor's own pages. Plans move often, so the check date is below.
| Tool | Open source | Where it runs | Free option | Price |
|---|---|---|---|---|
| Glider | Yes, Apache-2.0. | Self-hosted, one server in Docker, with S3-compatible storage as the source of truth. No replication. | Free to self-host. | No paid plan listed. You pay for your own server and bucket. |
| KiviDB | Yes, AGPL-3.0. | Self-hosted, or KiviDB Cloud on AWS, Google Cloud, Azure or your own cloud account. | Free to self-host. | Cloud: Essentials, Pro and Scale tiers, billed by the hour. See pricing. |
| Pinecone | No. | Managed on AWS, GCP or Azure. Bring-your-own-cloud runs it in your account. | Starter: 2 GB storage, 2M write units and 1M read units a month, up to 5 indexes, us-east-1 only. | Builder $20/mo flat. Standard $50/mo minimum, then pay as you go. Enterprise $500/mo minimum. |
| Qdrant | Yes, Apache-2.0. | Self-hosted, Qdrant Cloud on AWS, GCP or Azure, or Hybrid and Private Cloud on your own infrastructure. | Free tier: one-node cluster with 0.5 vCPU, 1 GB RAM and 4 GB disk. | Standard is usage-based, billed hourly on vCPU, memory, storage and backups. Premium has a minimum spend. |
| Weaviate | Yes, BSD-3-Clause. Some enterprise features need a license key. | Self-hosted, or Weaviate Cloud: shared on AWS or GCP, dedicated on AWS, GCP or Azure. | Free: 1 cluster, 100,000 objects, 1 GB memory, 10 GB disk. | Flex from $45/mo, pay as you go. Premium is a prepaid contract from $400/mo. |
| Chroma | Yes, Apache-2.0. | Self-hosted, or serverless Chroma Cloud. BYOC and single-tenant clusters on Enterprise. | Starter: $0/mo plus usage, with $5 in free credits. | $2.50 per GiB written, $0.33 per GiB stored a month, $0.0075 per TiB queried. Team $250/mo with $100 credits. Enterprise custom. |
Checked 2026-10-30. Sources: Pinecone pricing, Qdrant pricing, Qdrant on GitHub, Weaviate pricing, Weaviate license, Chroma pricing, Chroma on GitHub, Glider, Glider on GitHub, KiviDB pricing.
Pick it if.
- PineconeYou want nothing to run, with embeddings, reranking and search from one vendor.
- QdrantYou want open source you can self-host today and the same engine managed later, even on your own infrastructure.
- WeaviateYou want hybrid search and multi-tenancy, with embeddings hosted next to the data.
- ChromaYou want to start on your laptop and move to a serverless cloud billed per GiB.
- GliderYou want your vectors in your own S3 bucket, safe through a crash, and one server is enough.
- KiviDBYou already run Redis and want vector search without adding another database.
Each listing.
The directory page, alternatives in the same category, and a head-to-head where we have one.
- GliderAlternatives
- KiviDBAlternatives
- PineconeAlternatives
- QdrantAlternatives
- WeaviateAlternatives
- ChromaAlternatives
Category pages list every tool in that category, including ones left off this page. Built one of these? Get it featured in its category.
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