What is Faiss?
Faiss is a library for efficient similarity search and clustering of dense vectors. It contains algorithms that search in sets of vectors of any size, up to ones that possibly do not fit in RAM.
Faiss pricing
We don't have Faiss's full plan breakdown yet (its pricing page resisted automated reading). Here's what we could confirm. Always check live pricing for exact numbers.
What Faiss does
The capabilities that matter for vector databases, normalised so it lines up with every alternative. “-” means we haven't confirmed it, not that it's missing.
- Deployment
- Self-hosted
- Serverless / consumption pricing
- ✗
- ANN index (HNSW / IVF / DiskANN / ScaNN / flat)
- HNSW, IVF, PQ, multi-index, NSG
- Distance metrics (cosine / dot / Euclidean)
- Euclidean (L2), inner product, L1, Linf
- Metadata filtering
- -
- Hybrid search (dense + sparse fusion)
- -
- Built-in BM25 / lexical
- -
- Quantization
- Product
- On-disk vs in-memory
- Disk-backed
- Multi-tenancy (namespaces / collections / tenants)
- -
- Horizontal scale
- Single-node
- Consistency
- -
- Licence class
- Permissive OSS
- Purpose-built vs feature-of-parent
- Extension
Platform & deployment
Independently observed- macOS
- Linux
- Windows
- Self-hosted
Security & compliance
Known vulnerabilities: 0 (0 in the last 12 months) sourcea count reflects scale & disclosure, not quality
Faiss FAQ
Common questions about Faiss, answered from independent, dated evidence.
What is Faiss?
Faiss is a library for efficient similarity search and clustering of dense vectors. It contains algorithms that search in sets of vectors of any size, up to ones that possibly do not fit in RAM. It is indexed under Vector Databases.
Source: https://faiss.ai
Is Faiss free to use?
Faiss is open source, so it can be self-hosted and used at no licence cost. It is released under the MIT licence. Pricing changes often, so verify at source before relying on it.
Source: https://faiss.ai
What platforms does Faiss support?
Faiss supports Windows, macOS and Linux. Platforms we have not confirmed are simply not listed here rather than ruled out.
Source: https://faiss.ai
Can Faiss be self-hosted?
Yes. Faiss can be deployed self-hosted, so it does not have to run on the vendor's infrastructure.
Source: https://faiss.ai
Is Faiss open source?
Yes. Faiss is published under the MIT licence, a permissive licence that generally allows commercial use and modification. Licence terms can change between releases, so verify against the repository for the version you intend to use.
Faiss alternatives
Other vector databases we track, ranked by the same independent score.
- Zilliz CloudA fully managed cloud service for storing, indexing, and searching high-dimensional vector data at scalemedium · 74%
- PineconeManaged vector database infrastructure for machine learning applicationshigh · 75%
- TurbopufferA database combining vector similarity and text search built on cloud storagemedium · 61%
- EpsillaCreate AI agents without needing engineering resourceslow · 30%
- Chromamedium · 70%
- WeaviateA vector database platform designed for building AI-powered semantic search applicationshigh · 75%
Compare Faiss
Side by side against other vector databases, attribute by attribute, with a source on every value.
The vioscaleAI score: one lens on the evidence
Not user reviews and not a paid placement: a confidence-weighted blend of the independent signals below (adoption, activity, security posture, and more), which you can sort and re-weight yourself. Vendors can correct their listing but can never move their rank, and stars are weighted low as a vanity metric. It is one way to read the evidence for Faiss, not the verdict.
| Signal | Score | Weight | Contribution | Evidence |
|---|---|---|---|---|
| Development activity | 51 | 0.14 | 6.9 | ✓ |
| Release cadence | 54 | 0.08 | 4.4 | ✓ |
| Stars | 87 | 0.05 | 4.1 | ✓ |
| Dependent projects | 63 | 0.05 | 3.4 | ✓ |
| Security score | 61 | 0.05 | 3.3 | ✓ |
| Capabilities | 0 | 0.08 | 0.0 | - |
| Integrations | 0 | 0.05 | 0.0 | - |
| Security posture | 0 | 0.12 | 0.0 | - |
| Package downloads | 0 | 0.04 | 0.0 | - |
| Developer Q&A activity | 0 | 0.14 | 0.0 | - |
Computed . Re-weight it by intent, or see the full method.
All data & sourcesshow ↓
Every value we hold, with its source, retrieval date, and confidence. This is the evidence behind the score: don't trust it, verify it.
Activity
| Attribute | Value | Evidence |
|---|---|---|
| Commits last 30d | 40 | mediumsource · 2026-09-11 · 65% |
Adoption
Content
| Attribute | Value | Evidence |
|---|---|---|
| Faq | 5 items | mediumsource · 2026-09-10 · 67% |
Features
| Attribute | Value | Evidence |
|---|---|---|
| Capabilities | Ann index: HNSW, IVF, PQ, multi-index, NSG · Deployment: self_hosted · Serverless: No · Quantization: product · Storage tier: disk_backed · Licence class: permissive_oss | mediumsource · 2026-08-13 · 60% |
Language
| Attribute | Value | Evidence |
|---|---|---|
| Primary | C++ | highsource · 2026-09-11 · 90% |
License
| Attribute | Value | Evidence |
|---|---|---|
| Spdx | MIT | highsource · 2026-09-11 · 95% |
Pricing
Release
Reliability
| Attribute | Value | Evidence |
|---|---|---|
| Status page | Yes | mediumsource · 2026-08-03 · 60% |
Security
Is Faiss the right choice for you?
Tell us the job, the constraints and what you weigh most, and we will rank Faiss against the rest of the vector databases we index, using the same dated evidence weighted your way.
Free to run, no account needed to start. How the evaluation works
Is this your product?
This profile was built from public sources without asking you. You can take the badge below and use it anywhere, and you can claim the profile to correct anything we got wrong. Both are free, and neither moves Faiss up or down: nobody can buy rank here, including you.
Take the badge
Live, always current, and free to use on your own site. It shows Faiss's independent score and links back to this profile.
<a href="https://www.vioscale.ai/software/faiss" target="_blank" rel="noopener">
<img src="https://www.vioscale.ai/badge/software/faiss.svg" alt="Faiss, verified on vioscaleAI" width="330" height="76" loading="lazy" />
</a>Markdown, for a README →
[](https://www.vioscale.ai/software/faiss)Claim the profile
Verify you control the domain and you can correct the facts, add the sources we should be reading, and see how AI assistants are describing Faiss. Free, and it does not change the score.
- Correct anything wrong, with evidence
- Point our crawler at the pages that matter
- See which AI systems are reading this profile
Not the owner? How vendor profiles work