kitio.aiFaiss vs pgvector
A side-by-side look at pricing plans, free tiers, features, pros and cons, updated for 2026. Faiss starts at Free and pgvector starts at Free. Check both pricing pages for current plans.
At a glance
Best for
Category
Pricing model
Starting price
Free plan
Made by
Based in
Rating
Key features
- Nearest neighbor search
- Clustering
- GPU algorithms
- Python wrappers
- Indexes larger than RAM
- Evaluation tools
- Vector column type
- HNSW and IVFFlat indexes
- Multiple distance metrics
- Plain SQL queries
- Wide cloud support
| Feature | Faiss | pgvector |
|---|---|---|
| Best for | Open-source library for similarity search over dense vectors | Open-source vector similarity search extension for Postgres |
| Category | Models & APIs | Models & APIs |
| Pricing model | Free | Free |
| Starting price | Free | Free |
| Free plan | Yes, fully free | Yes, fully free |
| Made by | Meta FAIR | pgvector contributors |
| Based in | United States | – |
| Rating | No ratings yet | No ratings yet |
| Key features |
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Pricing compared
Faiss starts at Free and pgvector starts at Free. Check both pricing pages for current plans.
Free plan
Cheapest paid plan
Top plan
Free trial
Prices in USD, checked Oct 28, 2026 or later. Plans change often, so confirm on each tool's site before you buy.
Pros and cons
Faiss
- Free and open source
- Scales past available memory
- GPU support for key algorithms
- A library, not a managed service
- Needs engineering effort to deploy
- Not a database, so no built-in server or storage
pgvector
- Uses your existing database
- Free and widely supported
- Full SQL power
- Slower than specialized engines at scale
- Index builds use memory
- Tuning needs Postgres skills
Which one should you choose?
Choose Faiss if you want:
- Free and open source
- Scales past available memory
- GPU support for key algorithms
Watch out: a library, not a managed service.
Choose pgvector if you want:
- Uses your existing database
- Free and widely supported
- Full SQL power
Watch out: slower than specialized engines at scale.
Faiss vs pgvector FAQ
What is the difference between Faiss and pgvector?
Faiss: Open-source library for similarity search over dense vectors. pgvector: Open-source vector similarity search extension for Postgres. Both are models & apis tools.
Is Faiss or pgvector cheaper?
Faiss starts at Free and pgvector starts at Free. Check both pricing pages for current plans.
Do Faiss and pgvector have free plans?
Faiss: Yes, fully free. pgvector: Yes, fully free.
Who makes Faiss?
Faiss is made by Meta FAIR, based in United States.
Who makes pgvector?
pgvector is made by pgvector contributors.
Which should I choose, Faiss or pgvector?
Choose Faiss if you value free and open source and scales past available memory. Choose pgvector if you value uses your existing database and free and widely supported.