# sentence-transformers

> A Python module for working with embedding and reranking models

- **Canonical URI:** https://www.vioscale.ai/software/sentence-transformers
- **Category:** Embeddings Apis
- **Homepage:** https://www.sbert.net
- **Also known as:** sentence-transformers
- **Profile claimed by vendor:** no
- **Last updated:** 2026-10-14T22:42:56.681Z

## vioscaleAI score

**58.9 / 100**, confidence 54% (medium). Computed 2026-10-14.

Composite of weighted, independently-sourced signals (no user reviews, no vendor payment).

| Signal | Score | Weight | Contribution | Evidence present |
|---|--:|--:|--:|:--:|
| capabilities | 57.8 | 0.08 | 4.6 | ✓ |
| repo_stars | 80.8 | 0.047 | 3.8 | ✓ |
| integrations | 8.7 | 0.054 | 0.5 | ✓ |
| dependent_projects | 61.9 | 0.054 | 3.3 | ✓ |
| dev_activity | 63.1 | 0.135 | 8.5 | ✓ |
| release_cadence | 85 | 0.081 | 6.9 | ✓ |
| security_posture | 0 | 0.122 | 0 | - |
| package_downloads | 0 | 0.041 | 0 | - |
| security_score | 0 | 0.054 | 0 | - |
| community_qa_activity | 0 | 0.135 | 0 | - |

## Pricing

_As of 2026-08-21, [verify at source](https://www.sbert.net). Independently observed._

Open source · Free tier

## About

Python toolkit for generating semantic embeddings from text, images, audio, and video using transformer-based neural networks. Supports dense embedding models, cross-encoder rerankers for scoring and ranking, and late-interaction multi-vector models for advanced retrieval tasks.

_Independently observed._

## Platform & deployment
- **Deployment:** Self-hosted

## Integrations (1)

_Independently observed._

- Hugging Face Hub

## Capabilities

_The capabilities that matter for Embeddings Apis. "-" = undocumented, not absent._

| Capability | Supported |
|---|:--:|
| **Capabilities** | |
| Architecture model | Open weights local |
| Matryoshka representation learning for dimension truncation | - |
| Multilingual support across 100 plus languages | - |
| Binary and scalar quantization for memory reduction | - |
| Cross encoder reranker API offered | ✓ |
| Late interaction architecture colbert v2 | ✓ |
| Massive context window greater than 8k tokens | - |
| Multi modal image and text joint embeddings | ✓ |
| Task specific prefixes query vs document instructions | - |
| Zero data retention training opt out enterprise | - |
| SOC2 type ii | - |
| Mit or apache permissive oss license | - |
| Pricing model | Free open weights |

## Release history

| Version | Date | Type |
|---|---|---|
| [v6.1.0](https://github.com/huggingface/sentence-transformers/releases/tag/v6.1.0) | 2026-09-18 | stable |
| [v6.0.1](https://github.com/huggingface/sentence-transformers/releases/tag/v6.0.1) | 2026-08-31 | stable |
| [v6.0.0](https://github.com/huggingface/sentence-transformers/releases/tag/v6.0.0) | 2026-08-18 | stable |
| [v5.7.0](https://github.com/huggingface/sentence-transformers/releases/tag/v5.7.0) | 2026-08-06 | stable |
| [v5.6.1](https://github.com/huggingface/sentence-transformers/releases/tag/v5.6.1) | 2026-07-23 | stable |
| [v5.6.0](https://github.com/huggingface/sentence-transformers/releases/tag/v5.6.0) | 2026-06-16 | stable |
| [v5.5.1](https://github.com/huggingface/sentence-transformers/releases/tag/v5.5.1) | 2026-05-20 | stable |
| [v5.5.0](https://github.com/huggingface/sentence-transformers/releases/tag/v5.5.0) | 2026-05-12 | stable |
| [v5.4.1](https://github.com/huggingface/sentence-transformers/releases/tag/v5.4.1) | 2026-04-14 | stable |
| [v5.4.0](https://github.com/huggingface/sentence-transformers/releases/tag/v5.4.0) | 2026-04-09 | stable |
| [v5.3.0](https://github.com/huggingface/sentence-transformers/releases/tag/v5.3.0) | 2026-03-12 | stable |
| [v5.2.3](https://github.com/huggingface/sentence-transformers/releases/tag/v5.2.3) | 2026-02-17 | stable |
| [v5.2.2](https://github.com/huggingface/sentence-transformers/releases/tag/v5.2.2) | 2026-01-27 | stable |
| [v5.2.1](https://github.com/huggingface/sentence-transformers/releases/tag/v5.2.1) | 2026-01-26 | stable |
| [v5.2.0](https://github.com/huggingface/sentence-transformers/releases/tag/v5.2.0) | 2025-12-11 | stable |

_… and 5 earlier release(s)._

## Security & compliance


Known vulnerabilities: 1 (1 in the last 12 months), max severity CRITICAL ([source](https://advisories.ecosyste.ms/api/v1/advisories?ecosystem=pypi&package_name=sentence-transformers&per_page=100)). A count reflects scale and disclosure, not quality.

## FAQ

### What is sentence-transformers?

Python toolkit for generating semantic embeddings from text, images, audio, and video using transformer-based neural networks. Supports dense embedding models, cross-encoder rerankers for scoring and ranking, and late-interaction multi-vector models for advanced retrieval tasks. It is indexed under Embeddings Apis.

_Source: [https://www.sbert.net](https://www.sbert.net)._

### Is sentence-transformers free to use?

sentence-transformers is open source, so it can be self-hosted and used at no licence cost. It is released under the Apache-2.0 licence. Pricing changes often, so verify at source before relying on it.

_Source: [https://www.sbert.net](https://www.sbert.net)._

### Can sentence-transformers be self-hosted?

Yes. sentence-transformers can be deployed self-hosted, so it does not have to run on the vendor's infrastructure.

_Source: [https://www.sbert.net](https://www.sbert.net)._

### Is sentence-transformers open source?

Yes. sentence-transformers is published under the Apache-2.0 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.

_Source: [https://github.com/huggingface/sentence-transformers](https://github.com/huggingface/sentence-transformers)._


## Facts

Every value below carries its source and our confidence. Facts are re-crawled on a freshness schedule.

### pricing

| Attribute | Value | Source | Retrieved | Confidence |
|---|---|---|---|---|
| pricing.free_tier | yes | [link](https://www.sbert.net) | 2026-10-14 | 60% (medium) |
| pricing.model | open_source | [link](https://www.sbert.net) | 2026-10-14 | 60% (medium) |
| pricing.price_level | free | [link](https://www.sbert.net) | 2026-10-14 | 60% (medium) |
| pricing.transparent | yes | [link](https://www.sbert.net) | 2026-10-14 | 60% (medium) |

### integrations

| Attribute | Value | Source | Retrieved | Confidence |
|---|---|---|---|---|
| integrations.count | 1 | [link](https://www.sbert.net) | 2026-08-21 | 60% (medium) |

### market

| Attribute | Value | Source | Retrieved | Confidence |
|---|---|---|---|---|
| market.availability | `{"primaryMarkets":[],"availabilityScope":"global","availableCountries":[],"notAvailableCountries":[]}` | [link](https://www.sbert.net) | 2026-08-21 | 75% (high) |

### activity

| Attribute | Value | Source | Retrieved | Confidence |
|---|---|---|---|---|
| activity.commits_last_30d | 100 | [link](https://github.com/huggingface/sentence-transformers/pulse) | 2026-10-14 | 65% (medium) |

### adoption

| Attribute | Value | Source | Retrieved | Confidence |
|---|---|---|---|---|
| adoption.github_stars | 19,174 | [link](https://github.com/huggingface/sentence-transformers) | 2026-10-14 | 90% (high) |
| adoption.dependent_repos | 5,182 | [link](https://packages.ecosyste.ms/api/v1/packages/lookup?repository_url=https%3A%2F%2Fgithub.com%2Fhuggingface%2Fsentence-transformers) | 2026-10-14 | 85% (high) |

### language

| Attribute | Value | Source | Retrieved | Confidence |
|---|---|---|---|---|
| language.primary | Python | [link](https://github.com/huggingface/sentence-transformers) | 2026-10-14 | 90% (high) |

### license

| Attribute | Value | Source | Retrieved | Confidence |
|---|---|---|---|---|
| license.spdx | Apache-2.0 | [link](https://github.com/huggingface/sentence-transformers) | 2026-10-14 | 95% (high) |

### release

| Attribute | Value | Source | Retrieved | Confidence |
|---|---|---|---|---|
| release.cadence_days | 27 | [link](https://github.com/huggingface/sentence-transformers/releases) | 2026-10-14 | 70% (medium) |

### security

| Attribute | Value | Source | Retrieved | Confidence |
|---|---|---|---|---|
| security.vulnerabilities | `{"count":1,"source":"https://advisories.ecosyste.ms/api/v1/advisories?ecosystem=pypi&package_name=sentence-transformers&per_page=100","last_12m":1,"max_severity":"CRITICAL"}` | [link](https://advisories.ecosyste.ms/api/v1/advisories?ecosystem=pypi&package_name=sentence-transformers&per_page=100) | 2026-10-14 | 90% (high) |

### content

| Attribute | Value | Source | Retrieved | Confidence |
|---|---|---|---|---|
| content.faq | `[{"answer":"Python toolkit for generating semantic embeddings from text, images, audio, and video using transformer-based neural networks. Supports dense embedding models, cross-encoder rerankers for scoring and ranking, and late-interaction multi-vector models for advanced retrieval tasks. It is indexed under Embeddings Apis.","source":"https://www.sbert.net","question":"What is sentence-transformers?","confidence":0.6},{"answer":"sentence-transformers is open source, so it can be self-hosted and used at no licence cost. It is released under the Apache-2.0 licence. Pricing changes often, so verify at source before relying on it.","source":"https://www.sbert.net","question":"Is sentence-transformers free to use?","confidence":0.6},{"answer":"Yes. sentence-transformers can be deployed self-hosted, so it does not have to run on the vendor's infrastructure.","source":"https://www.sbert.net","question":"Can sentence-transformers be self-hosted?","confidence":0.6},{"answer":"Yes. sentence-transformers is published under the Apache-2.0 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.","source":"https://github.com/huggingface/sentence-transformers","question":"Is sentence-transformers open source?","confidence":0.95}]` | [link](https://www.sbert.net) | 2026-09-10 | 69% (medium) |

---
*Source: vioscaleAI (https://www.vioscale.ai/software/sentence-transformers). Independent, evidence-based software intelligence. Cite the canonical URI.*