# Flask vs Ruby on Rails

**Leader by vioscaleAI score:** Ruby on Rails

| Attribute | Flask | Ruby on Rails |
|---|---|---|
| **vioscaleAI score** | 63.1 (66% (medium)) | 71.8 (51% (medium)) |
| activity.commits_last_30d | 11 | 100 |
| adoption.dependent_repos | 119,058 | 1,358,186 |
| adoption.github_stars | 74,889 | 58,803 |
| content.faq | `[{"answer":"A Python web framework that makes it straightforward for developers to start building web applications, while maintaining the capability to handle large and sophisticated projects. It is indexed under Web Frameworks.","source":"https://flask.palletsprojects.com","question":"What is Flask?","confidence":0.6},{"answer":"Flask is open source, so it can be self-hosted and used at no licence cost. It is released under the BSD-3-Clause licence. Pricing changes often, so verify at source before relying on it.","source":"https://flask.palletsprojects.com","question":"Is Flask free to use?","confidence":0.6},{"answer":"Flask supports the web and a command-line interface. Platforms we have not confirmed are simply not listed here rather than ruled out.","source":"https://flask.palletsprojects.com","question":"What platforms does Flask support?","confidence":0.6},{"answer":"Yes. Flask is published under the BSD-3-Clause 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/pallets/flask","question":"Is Flask open source?","confidence":0.95}]` | `[{"answer":"A complete web application framework for Ruby that provides integrated tools, libraries, and conventions for building database-backed web applications across the full stack—from database models to frontend templates and controllers. It is indexed under Web Frameworks.","source":"https://rubyonrails.org","question":"What is Ruby on Rails?","confidence":0.6},{"answer":"Ruby on Rails 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://rubyonrails.org","question":"Is Ruby on Rails free to use?","confidence":0.6},{"answer":"Ruby on Rails supports the web and a command-line interface. Platforms we have not confirmed are simply not listed here rather than ruled out.","source":"https://rubyonrails.org","question":"What platforms does Ruby on Rails support?","confidence":0.6},{"answer":"Yes. Ruby on Rails can be deployed cloud / SaaS and self-hosted, so it does not have to run on the vendor's infrastructure.","source":"https://rubyonrails.org","question":"Can Ruby on Rails be self-hosted?","confidence":0.6},{"answer":"Yes. Ruby on Rails 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.","source":"https://github.com/rails/rails","question":"Is Ruby on Rails open source?","confidence":0.95}]` |
| deployment.options | - | `{"cloud":true,"self_hosted":true}` |
| description.long | A Python-based web framework that emphasizes simple setup while scaling to support complex, production-grade applications | A full-stack framework for building web applications with integrated database modeling, templating, email handling, real-time WebSocket support, background job processing, and security features. |
| features.capabilities | `{"language":"Python","rendering":"ssr","api_routes":true,"hot_reload":true,"file_routing":false,"streaming_ssr":true,"language_runtime":"Python","typescript_first":false,"architecture_style":"minimalist","templating_included":true,"testing_framework_included":true}` | `{"language":"Ruby","rendering":"ssr","api_routes":true,"file_routing":true,"license_type":"MIT/BSD","orm_included":true,"cli_scaffolding":true,"language_runtime":"Ruby","typescript_first":false,"websocket_support":true,"architecture_style":"full-stack-mvc","templating_included":true,"background_jobs_included":true}` |
| language.primary | Python | Ruby |
| license.spdx | BSD-3-Clause | MIT |
| market.availability | `{"primaryMarkets":[],"availabilityScope":"global","availableCountries":[],"notAvailableCountries":[]}` | - |
| platform.support | `{"cli":true,"web":true}` | `{"web":true}` |
| pricing | `{"type":"open_source","sourceUrl":"https://flask.palletsprojects.com","retrievedAt":"2026-09-07T13:13:42.073Z"}` | `{"type":"open_source","sourceUrl":"https://rubyonrails.org","retrievedAt":"2026-08-16T21:36:16.955Z"}` |
| pricing.free_tier | yes | yes |
| pricing.model | open_source | open_source |
| pricing.price_level | free | free |
| release.cadence_days | 63 | - |
| release.history | `[{"url":"https://github.com/pallets/flask/releases/tag/3.1.3","date":"2026-02-19T05:01:30Z","type":"stable","version":"3.1.3"},{"url":"https://github.com/pallets/flask/releases/tag/3.1.2","date":"2025-08-19T21:03:31Z","type":"stable","version":"3.1.2"},{"url":"https://github.com/pallets/flask/releases/tag/3.1.1","date":"2025-05-13T15:01:32Z","type":"stable","version":"3.1.1"},{"url":"https://github.com/pallets/flask/releases/tag/3.1.0","date":"2024-11-13T18:29:05Z","type":"stable","version":"3.1.0"},{"url":"https://github.com/pallets/flask/releases/tag/3.0.3","date":"2024-04-07T19:27:16Z","type":"stable","version":"3.0.3"},{"url":"https://github.com/pallets/flask/releases/tag/3.0.2","date":"2024-02-03T21:12:56Z","type":"stable","version":"3.0.2"},{"url":"https://github.com/pallets/flask/releases/tag/3.0.1","date":"2024-01-18T20:03:56Z","type":"stable","version":"3.0.1"},{"url":"https://github.com/pallets/flask/releases/tag/3.0.0","date":"2023-09-30T14:38:50Z","type":"stable","version":"3.0.0"},{"url":"https://github.com/pallets/flask/releases/tag/2.3.3","date":"2023-08-21T19:52:49Z","type":"stable","version":"2.3.3"},{"url":"https://github.com/pallets/flask/releases/tag/2.2.5","date":"2023-05-02T14:43:59Z","type":"stable","version":"2.2.5"},{"url":"https://github.com/pallets/flask/releases/tag/2.3.2","date":"2023-05-01T15:43:14Z","type":"stable","version":"2.3.2"},{"url":"https://github.com/pallets/flask/releases/tag/2.3.1","date":"2023-04-25T21:22:11Z","type":"stable","version":"2.3.1"},{"url":"https://github.com/pallets/flask/releases/tag/2.3.0","date":"2023-04-25T18:43:20Z","type":"stable","version":"2.3.0"},{"url":"https://github.com/pallets/flask/releases/tag/2.2.4","date":"2023-04-25T17:53:24Z","type":"stable","version":"2.2.4"},{"url":"https://github.com/pallets/flask/releases/tag/2.2.3","date":"2023-02-15T22:44:40Z","type":"stable","version":"2.2.3"},{"url":"https://github.com/pallets/flask/releases/tag/2.2.2","date":"2022-08-08T23:28:14Z","type":"stable","version":"2.2.2"},{"url":"https://github.com/pallets/flask/releases/tag/2.2.1","date":"2022-08-03T23:53:45Z","type":"stable","version":"2.2.1"},{"url":"https://github.com/pallets/flask/releases/tag/2.2.0","date":"2022-08-02T00:20:32Z","type":"stable","version":"2.2.0"},{"url":"https://github.com/pallets/flask/releases/tag/2.1.3","date":"2022-07-13T21:01:09Z","type":"stable","version":"2.1.3"},{"url":"https://github.com/pallets/flask/releases/tag/2.1.2","date":"2022-04-28T17:48:46Z","type":"stable","version":"2.1.2"}]` | `[{"url":"https://github.com/rails/rails/releases/tag/v8.1.4","date":"2026-09-24T14:19:52Z","type":"stable","version":"v8.1.4"},{"url":"https://github.com/rails/rails/releases/tag/v7.2.4","date":"2026-09-24T16:28:35Z","type":"stable","version":"v7.2.4"},{"url":"https://github.com/rails/rails/releases/tag/v8.1.3.1","date":"2026-07-29T14:59:54Z","type":"stable","version":"v8.1.3.1"},{"url":"https://github.com/rails/rails/releases/tag/v8.0.5.1","date":"2026-07-29T15:08:22Z","type":"stable","version":"v8.0.5.1"},{"url":"https://github.com/rails/rails/releases/tag/v7.2.3.2","date":"2026-07-29T15:05:22Z","type":"stable","version":"v7.2.3.2"},{"url":"https://github.com/rails/rails/releases/tag/v8.1.3","date":"2026-03-24T20:26:02Z","type":"stable","version":"v8.1.3"},{"url":"https://github.com/rails/rails/releases/tag/v8.0.5","date":"2026-03-24T20:19:33Z","type":"stable","version":"v8.0.5"},{"url":"https://github.com/rails/rails/releases/tag/v8.1.2.1","date":"2026-03-23T19:42:42Z","type":"stable","version":"v8.1.2.1"},{"url":"https://github.com/rails/rails/releases/tag/v8.0.4.1","date":"2026-03-23T19:38:25Z","type":"stable","version":"v8.0.4.1"},{"url":"https://github.com/rails/rails/releases/tag/v7.2.3.1","date":"2026-03-23T19:32:34Z","type":"stable","version":"v7.2.3.1"},{"url":"https://github.com/rails/rails/releases/tag/v8.1.2","date":"2026-01-08T20:17:17Z","type":"stable","version":"v8.1.2"},{"url":"https://github.com/rails/rails/releases/tag/v8.1.1","date":"2025-10-28T23:46:29Z","type":"stable","version":"v8.1.1"},{"url":"https://github.com/rails/rails/releases/tag/v8.0.4","date":"2025-10-28T23:43:23Z","type":"stable","version":"v8.0.4"},{"url":"https://github.com/rails/rails/releases/tag/v7.2.3","date":"2025-10-28T23:24:18Z","type":"stable","version":"v7.2.3"},{"url":"https://github.com/rails/rails/releases/tag/v7.1.6","date":"2025-10-28T23:19:19Z","type":"stable","version":"v7.1.6"},{"url":"https://github.com/rails/rails/releases/tag/v7.0.10","date":"2025-10-28T23:12:55Z","type":"stable","version":"v7.0.10"},{"url":"https://github.com/rails/rails/releases/tag/v7.0.9","date":"2025-10-28T23:02:29Z","type":"stable","version":"v7.0.9"},{"url":"https://github.com/rails/rails/releases/tag/v8.1.0","date":"2025-10-22T00:35:05Z","type":"stable","version":"v8.1.0"},{"url":"https://github.com/rails/rails/releases/tag/v8.1.0.rc1","date":"2025-10-15T00:50:43Z","type":"prerelease","version":"v8.1.0.rc1"},{"url":"https://github.com/rails/rails/releases/tag/v8.0.3","date":"2025-09-22T22:19:48Z","type":"stable","version":"v8.0.3"}]` |
| reliability.status_page | yes | - |
| security.disclosure_policy | - | yes |
| security.scorecard | 7.1 | 6.4 |
| security.trust_center | - | https://rubyonrails.org/security |
| security.vulnerabilities | `{"count":5,"source":"https://advisories.ecosyste.ms/api/v1/advisories?ecosystem=pypi&package_name=flask&per_page=100","last_12m":1,"max_severity":"HIGH"}` | `{"count":18,"source":"https://advisories.ecosyste.ms/api/v1/advisories?ecosystem=rubygems&package_name=activesupport&per_page=100","last_12m":3,"max_severity":"CRITICAL"}` |

## Capabilities (Web Frameworks)

| Capability | Flask | Ruby on Rails |
|---|:--:|:--:|
| **Core** |  |  |
| Rendering model | Server-side | Server-side |
| File-based routing | ✗ | ✓ |
| Language | Python | Ruby |
| **Rendering** |  |  |
| Server components | - | - |
| Streaming SSR | ✓ | - |
| **Fullstack** |  |  |
| Built-in API / backend routes | ✓ | ✓ |
| **DX** |  |  |
| First-class TypeScript | ✗ | ✗ |
| Fast refresh / HMR | ✓ | - |
| **Deployment** |  |  |
| Edge runtime support | - | - |

*Source: vioscaleAI. Generated 2026-10-16T20:06:15.794Z. "-" = undocumented, not absent.*