# Flask vs Spring Boot

| Attribute | Flask | Spring Boot |
|---|---|---|
| **vioscaleAI score** | 63.1 (66% (medium)) | 65.8 (51% (medium)) |
| activity.commits_last_30d | 11 | 100 |
| adoption.dependent_repos | 119,058 | 164,184 |
| adoption.github_stars | 74,889 | 81,557 |
| 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 Spring-based framework that provides opinionated defaults and pre-configured dependencies to simplify Java application development, allowing developers to create deployable applications without extensive setup. It is indexed under Web Frameworks.","source":"https://spring.io/projects/spring-boot","question":"What is Spring Boot?","confidence":0.6},{"answer":"Yes. Spring Boot can be deployed self-hosted, so it does not have to run on the vendor's infrastructure.","source":"https://spring.io/projects/spring-boot","question":"Can Spring Boot be self-hosted?","confidence":0.6},{"answer":"Yes. Spring Boot 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/spring-projects/spring-boot","question":"Is Spring Boot open source?","confidence":0.95}]` |
| deployment.options | - | `{"self_hosted":true}` |
| description.long | A Python-based web framework that emphasizes simple setup while scaling to support complex, production-grade applications | Enables developers to create complete server applications quickly using embedded web servers, automatic dependency configuration, and built-in operational 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":"Java","api_routes":true,"server_components":true,"architecture_style":"structured-di","dependency_injection":true}` |
| language.primary | Python | Java |
| license.spdx | BSD-3-Clause | Apache-2.0 |
| market.availability | `{"primaryMarkets":[],"availabilityScope":"global","availableCountries":[],"notAvailableCountries":[]}` | - |
| platform.support | `{"cli":true,"web":true}` | - |
| pricing | `{"type":"open_source","sourceUrl":"https://flask.palletsprojects.com","retrievedAt":"2026-09-07T13:13:42.073Z"}` | `{"type":"hybrid","freeTier":true,"sourceUrl":"https://spring.io/projects/spring-boot","retrievedAt":"2026-10-05T11:07:44.884Z"}` |
| pricing.free_tier | yes | yes |
| pricing.model | open_source | freemium |
| pricing.price_level | free | low |
| 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/spring-projects/spring-boot/releases/tag/v4.2.0-M2","date":"2026-09-24T10:38:37Z","type":"prerelease","version":"v4.2.0-M2"},{"url":"https://github.com/spring-projects/spring-boot/releases/tag/v4.2.0-M1","date":"2026-08-20T20:09:59Z","type":"prerelease","version":"v4.2.0-M1"},{"url":"https://github.com/spring-projects/spring-boot/releases/tag/v4.1.1","date":"2026-08-20T20:02:36Z","type":"stable","version":"v4.1.1"},{"url":"https://github.com/spring-projects/spring-boot/releases/tag/v4.0.8","date":"2026-08-21T02:39:58Z","type":"stable","version":"v4.0.8"},{"url":"https://github.com/spring-projects/spring-boot/releases/tag/v3.5.16","date":"2026-06-25T11:00:26Z","type":"stable","version":"v3.5.16"},{"url":"https://github.com/spring-projects/spring-boot/releases/tag/v4.1.0","date":"2026-06-10T18:21:42Z","type":"stable","version":"v4.1.0"},{"url":"https://github.com/spring-projects/spring-boot/releases/tag/v4.0.7","date":"2026-06-10T18:50:46Z","type":"stable","version":"v4.0.7"},{"url":"https://github.com/spring-projects/spring-boot/releases/tag/v3.5.15","date":"2026-06-10T19:30:46Z","type":"stable","version":"v3.5.15"},{"url":"https://github.com/spring-projects/spring-boot/releases/tag/v4.1.0-RC1","date":"2026-04-23T15:54:20Z","type":"prerelease","version":"v4.1.0-RC1"},{"url":"https://github.com/spring-projects/spring-boot/releases/tag/v4.0.6","date":"2026-04-23T15:39:24Z","type":"stable","version":"v4.0.6"},{"url":"https://github.com/spring-projects/spring-boot/releases/tag/v3.5.14","date":"2026-04-23T16:01:25Z","type":"stable","version":"v3.5.14"},{"url":"https://github.com/spring-projects/spring-boot/releases/tag/v4.1.0-M4","date":"2026-03-26T11:04:53Z","type":"prerelease","version":"v4.1.0-M4"},{"url":"https://github.com/spring-projects/spring-boot/releases/tag/v4.0.5","date":"2026-03-26T11:05:31Z","type":"stable","version":"v4.0.5"},{"url":"https://github.com/spring-projects/spring-boot/releases/tag/v3.5.13","date":"2026-03-26T11:03:01Z","type":"stable","version":"v3.5.13"},{"url":"https://github.com/spring-projects/spring-boot/releases/tag/v4.1.0-M3","date":"2026-03-20T02:49:46Z","type":"prerelease","version":"v4.1.0-M3"},{"url":"https://github.com/spring-projects/spring-boot/releases/tag/v4.0.4","date":"2026-03-19T13:51:25Z","type":"stable","version":"v4.0.4"},{"url":"https://github.com/spring-projects/spring-boot/releases/tag/v3.5.12","date":"2026-03-19T14:01:08Z","type":"stable","version":"v3.5.12"},{"url":"https://github.com/spring-projects/spring-boot/releases/tag/v4.1.0-M2","date":"2026-02-19T18:05:50Z","type":"prerelease","version":"v4.1.0-M2"},{"url":"https://github.com/spring-projects/spring-boot/releases/tag/v4.0.3","date":"2026-02-19T14:02:24Z","type":"stable","version":"v4.0.3"},{"url":"https://github.com/spring-projects/spring-boot/releases/tag/v3.5.11","date":"2026-02-19T11:51:10Z","type":"stable","version":"v3.5.11"}]` |
| reliability.status_page | yes | yes |
| security.disclosure_policy | - | yes |
| security.scorecard | 7.1 | 7.2 |
| 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":2,"source":"https://advisories.ecosyste.ms/api/v1/advisories?ecosystem=maven&package_name=org.springframework.boot%3Aspring-boot-starter-actuator&per_page=100","last_12m":2,"max_severity":"HIGH"}` |

## Capabilities (Web Frameworks)

| Capability | Flask | Spring Boot |
|---|:--:|:--:|
| **Core** |  |  |
| Rendering model | Server-side | - |
| File-based routing | ✗ | - |
| Language | Python | Java |
| **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 2026-10-16T17:47:18.107Z. "-" = undocumented, not absent.*