# Fastify vs Flask

| Attribute | Fastify | Flask |
|---|---|---|
| **Vioscale score** | 63.9 (78% (high)) | 62.7 (68% (medium)) |
| activity.commits_last_30d | 69 | 16 |
| adoption.dependent_repos | 16,712 | 119,058 |
| adoption.github_stars | 37,024 | 72,136 |
| deployment.options | `{"self_hosted":true}` | - |
| description.long | A Node.js web framework optimized to handle high request volumes with minimal overhead, featuring a plugin system, JSON Schema validation, and native TypeScript support. | Flask is a Python-based web framework that emphasizes ease of use and quick setup while supporting complex applications. It provides built-in routing, template rendering, and session management, with extensibility through community-maintained extensions. |
| features.capabilities | `{"language":"JavaScript/TypeScript","api_routes":true,"typescript_first":true}` | `{"language":"Python","rendering":"ssr","api_routes":true,"hot_reload":true,"file_routing":false,"streaming_ssr":true,"typescript_first":false}` |
| integrations.count | 17 | - |
| integrations.list | `[{"name":"Next.js"},{"name":"Apollo Server"},{"name":"Angular"},{"name":"PostgreSQL"},{"name":"MongoDB"},{"name":"Redis"},{"name":"Elasticsearch"},{"name":"Swagger/OpenAPI"},{"name":"WebSocket"},{"name":"JWT"},{"name":"Helmet"},{"name":"Sentry"},{"name":"RabbitMQ"},{"name":"CORS"},{"name":"CSRF"},{"name":"OAuth2"},{"name":"Kubernetes"}]` | - |
| language.primary | JavaScript | Python |
| license.spdx | MIT | BSD-3-Clause |
| market.availability | - | `{"primaryMarkets":[],"availabilityScope":"global","availableCountries":[],"notAvailableCountries":[]}` |
| platform.support | - | `{"cli":true,"web":true}` |
| pricing | `{"type":"open_source","freeTier":true,"sourceUrl":"https://fastify.dev","retrievedAt":"2026-08-16T21:34:26.497Z"}` | `{"type":"open_source","freeTier":true,"sourceUrl":"https://flask.palletsprojects.com","retrievedAt":"2026-08-16T21:34:45.460Z"}` |
| pricing.free_tier | yes | yes |
| pricing.model | commercial | open_source |
| pricing.price_level | free | free |
| release.cadence_days | 3 | 63 |
| release.history | `[{"url":"https://github.com/fastify/fastify/releases/tag/v6.0.0-alpha.2","date":"2026-08-19T01:54:36Z","type":"prerelease","version":"v6.0.0-alpha.2"},{"url":"https://github.com/fastify/fastify/releases/tag/v5.12.1","date":"2026-08-18T19:51:41Z","type":"stable","version":"v5.12.1"},{"url":"https://github.com/fastify/fastify/releases/tag/v6.0.0-alpha.1","date":"2026-08-13T15:57:10Z","type":"prerelease","version":"v6.0.0-alpha.1"},{"url":"https://github.com/fastify/fastify/releases/tag/v5.12.0","date":"2026-08-13T15:55:21Z","type":"stable","version":"v5.12.0"},{"url":"https://github.com/fastify/fastify/releases/tag/v6.0.0-alpha.0","date":"2026-08-11T08:32:37Z","type":"prerelease","version":"v6.0.0-alpha.0"},{"url":"https://github.com/fastify/fastify/releases/tag/v5.11.3","date":"2026-08-08T06:55:46Z","type":"stable","version":"v5.11.3"},{"url":"https://github.com/fastify/fastify/releases/tag/v5.11.2","date":"2026-08-03T08:21:47Z","type":"stable","version":"v5.11.2"},{"url":"https://github.com/fastify/fastify/releases/tag/v5.11.1","date":"2026-08-03T08:10:10Z","type":"stable","version":"v5.11.1"},{"url":"https://github.com/fastify/fastify/releases/tag/v5.11.0","date":"2026-07-30T09:32:16Z","type":"stable","version":"v5.11.0"},{"url":"https://github.com/fastify/fastify/releases/tag/v5.10.0","date":"2026-07-05T09:37:06Z","type":"stable","version":"v5.10.0"},{"url":"https://github.com/fastify/fastify/releases/tag/v5.9.0","date":"2026-06-28T08:21:36Z","type":"stable","version":"v5.9.0"},{"url":"https://github.com/fastify/fastify/releases/tag/v5.8.5","date":"2026-04-14T12:09:02Z","type":"stable","version":"v5.8.5"},{"url":"https://github.com/fastify/fastify/releases/tag/v5.8.4","date":"2026-03-23T10:31:20Z","type":"stable","version":"v5.8.4"},{"url":"https://github.com/fastify/fastify/releases/tag/v5.8.3","date":"2026-03-23T10:20:21Z","type":"stable","version":"v5.8.3"},{"url":"https://github.com/fastify/fastify/releases/tag/v5.8.2","date":"2026-03-07T09:42:46Z","type":"stable","version":"v5.8.2"},{"url":"https://github.com/fastify/fastify/releases/tag/v5.8.1","date":"2026-03-05T10:10:57Z","type":"stable","version":"v5.8.1"},{"url":"https://github.com/fastify/fastify/releases/tag/v5.8.0","date":"2026-03-05T09:33:05Z","type":"stable","version":"v5.8.0"},{"url":"https://github.com/fastify/fastify/releases/tag/v5.7.4","date":"2026-02-02T18:23:39Z","type":"stable","version":"v5.7.4"},{"url":"https://github.com/fastify/fastify/releases/tag/v5.7.3","date":"2026-02-02T17:57:52Z","type":"stable","version":"v5.7.3"},{"url":"https://github.com/fastify/fastify/releases/tag/v5.7.2","date":"2026-01-26T11:15:54Z","type":"stable","version":"v5.7.2"}]` | `[{"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"}]` |
| security.scorecard | 8.3 | 7.1 |
| security.vulnerabilities | `{"count":10,"source":"https://advisories.ecosyste.ms/api/v1/advisories?ecosystem=npm&package_name=fastify&per_page=100","last_12m":5,"max_severity":"HIGH"}` | `{"count":5,"source":"https://advisories.ecosyste.ms/api/v1/advisories?ecosystem=pypi&package_name=flask&per_page=100","last_12m":1,"max_severity":"HIGH"}` |

## Capabilities (Web Frameworks)

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

*Source: Vioscale. Generated 2026-09-01T16:44:04.817Z. "-" = undocumented, not absent.*