# Checkstyle vs flake8

| Attribute | Checkstyle | flake8 |
|---|---|---|
| **vioscaleAI score** | 60.1 (49% (low)) | 64 (66% (medium)) |
| activity.commits_last_30d | 100 | 21 |
| adoption.dependent_repos | 1,425 | 153,063 |
| adoption.github_stars | 9,599 | 3,828 |
| adoption.package_downloads_weekly | - | 9,519,717 |
| content.faq | `[{"answer":"A development tool that automatically scans Java code to verify adherence to coding standards, detecting style violations, design problems, and formatting issues. Supports customizable rule sets and integrates with build tools and IDEs. It is indexed under Code Quality Tools.","source":"https://checkstyle.org/","question":"What is Checkstyle?","confidence":0.6},{"answer":"Checkstyle supports a command-line interface. Platforms we have not confirmed are simply not listed here rather than ruled out.","source":"https://checkstyle.org/","question":"What platforms does Checkstyle support?","confidence":0.6},{"answer":"Yes. Checkstyle can be deployed self-hosted, so it does not have to run on the vendor's infrastructure.","source":"https://checkstyle.org/","question":"Can Checkstyle be self-hosted?","confidence":0.6},{"answer":"Yes. Checkstyle is published under the LGPL-2.1 licence, a copyleft licence, so check its terms before embedding it in a closed-source product. Licence terms can change between releases, so verify against the repository for the version you intend to use.","source":"https://github.com/checkstyle/checkstyle","question":"Is Checkstyle open source?","confidence":0.95}]` | `[{"answer":"flake8 is an open-source Python linter that combines multiple style-checking tools to verify code compliance with PEP 8 and detect errors. It uses a plugin architecture for extensibility and is commonly integrated into development workflows and CI/CD pipelines. It is indexed under Code Quality Tools.","source":"https://flake8.pycqa.org/","question":"What is flake8?","confidence":0.6},{"answer":"flake8 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://flake8.pycqa.org/","question":"Is flake8 free to use?","confidence":0.6},{"answer":"flake8 supports a command-line interface. Platforms we have not confirmed are simply not listed here rather than ruled out.","source":"https://flake8.pycqa.org/","question":"What platforms does flake8 support?","confidence":0.6},{"answer":"Yes. flake8 can be deployed self-hosted, so it does not have to run on the vendor's infrastructure.","source":"https://flake8.pycqa.org/","question":"Can flake8 be self-hosted?","confidence":0.6},{"answer":"We have confirmed 3 integrations for flake8, including pycodestyle, pyflakes and mccabe. This is what we could verify from public sources, so the vendor may support others we have not indexed.","source":"https://flake8.pycqa.org/","question":"What does flake8 integrate with?","confidence":0.6},{"answer":"Yes. flake8 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://pypi.org/pypi/flake8/json","question":"Is flake8 open source?","confidence":0.9}]` |
| deployment.options | `{"self_hosted":true}` | `{"self_hosted":true}` |
| description.long | Checkstyle analyzes Java source code against configurable rules covering naming, imports, formatting, Javadoc, and class design. It enables teams to maintain consistent coding standards through CLI, IDE plugins, and CI/CD integrations. | flake8 is an open-source Python linter that combines multiple style-checking tools to verify code compliance with PEP 8 and detect errors. It uses a plugin architecture for extensibility and is commonly integrated into development workflows and CI/CD pipelines. |
| features.capabilities | `{"autofix":false,"metrics":true,"function":"static_analyzer","ci_gating":true,"deployment":"cli_local","open_source":"oss","config_model":"config_file","custom_rules":true,"impl_language":"Java","pricing_model":"free","language_scope":"single_language","editor_integration":true}` | `{"autofix":false,"metrics":true,"function":"linter","ci_gating":true,"deployment":"cli_local","open_source":"oss","config_model":"config_file","custom_rules":true,"impl_language":"Python","pricing_model":"free","language_scope":"single_language","editor_integration":true}` |
| integrations.count | 7 | 3 |
| integrations.list | `[{"name":"Maven"},{"name":"Ant"},{"name":"Eclipse","native":true,"category":"ide"},{"name":"IntelliJ IDEA","native":true,"category":"ide"},{"name":"Neovim","native":true,"category":"editor"},{"name":"Code Climate","native":true,"category":"code_quality"},{"name":"GitHub Actions","native":true,"category":"ci"},{"name":"Apache Ant","native":true,"category":"build_tool"}]` | `[{"name":"pycodestyle"},{"name":"pyflakes"},{"name":"mccabe"},{"name":"pre-commit","native":true,"category":"ci","direction":"inbound"}]` |
| language.primary | Java | Python |
| license.spdx | LGPL-2.1 | MIT |
| platform.support | `{"cli":true}` | `{"cli":true}` |
| pricing | `{"type":"open_source","sourceUrl":"https://checkstyle.org/","retrievedAt":"2026-10-14T22:30:54.455Z"}` | `{"type":"free","freeTier":true,"sourceUrl":"https://flake8.pycqa.org/","retrievedAt":"2026-09-10T16:03:57.147Z"}` |
| pricing.free_tier | yes | yes |
| pricing.model | open_source | free |
| pricing.price_level | free | free |
| pricing.transparent | yes | yes |
| release.cadence_days | 13 | - |
| release.history | `[{"url":"https://github.com/checkstyle/checkstyle/releases/tag/checkstyle-14.3.0","date":"2026-09-27T15:22:48Z","type":"stable","version":"checkstyle-14.3.0"},{"url":"https://github.com/checkstyle/checkstyle/releases/tag/checkstyle-14.2.0","date":"2026-09-27T14:43:29Z","type":"stable","version":"checkstyle-14.2.0"},{"url":"https://github.com/checkstyle/checkstyle/releases/tag/checkstyle-14.1.0","date":"2026-08-30T14:47:48Z","type":"stable","version":"checkstyle-14.1.0"},{"url":"https://github.com/checkstyle/checkstyle/releases/tag/checkstyle-14.0.0","date":"2026-08-18T13:09:20Z","type":"stable","version":"checkstyle-14.0.0"},{"url":"https://github.com/checkstyle/checkstyle/releases/tag/checkstyle-13.11.0","date":"2026-08-16T21:52:20Z","type":"stable","version":"checkstyle-13.11.0"},{"url":"https://github.com/checkstyle/checkstyle/releases/tag/checkstyle-13.10.0","date":"2026-08-09T17:48:41Z","type":"stable","version":"checkstyle-13.10.0"},{"url":"https://github.com/checkstyle/checkstyle/releases/tag/checkstyle-13.9.0","date":"2026-07-27T01:04:59Z","type":"stable","version":"checkstyle-13.9.0"},{"url":"https://github.com/checkstyle/checkstyle/releases/tag/checkstyle-13.8.0","date":"2026-07-12T02:55:15Z","type":"stable","version":"checkstyle-13.8.0"},{"url":"https://github.com/checkstyle/checkstyle/releases/tag/checkstyle-13.7.0","date":"2026-06-28T15:13:54Z","type":"stable","version":"checkstyle-13.7.0"},{"url":"https://github.com/checkstyle/checkstyle/releases/tag/checkstyle-13.6.0","date":"2026-06-15T03:24:52Z","type":"stable","version":"checkstyle-13.6.0"},{"url":"https://github.com/checkstyle/checkstyle/releases/tag/checkstyle-13.5.0","date":"2026-05-30T20:22:13Z","type":"stable","version":"checkstyle-13.5.0"},{"url":"https://github.com/checkstyle/checkstyle/releases/tag/checkstyle-13.4.2","date":"2026-05-02T04:07:51Z","type":"stable","version":"checkstyle-13.4.2"},{"url":"https://github.com/checkstyle/checkstyle/releases/tag/checkstyle-13.4.1","date":"2026-04-27T12:43:10Z","type":"stable","version":"checkstyle-13.4.1"},{"url":"https://github.com/checkstyle/checkstyle/releases/tag/checkstyle-13.4.0","date":"2026-03-29T17:41:44Z","type":"stable","version":"checkstyle-13.4.0"},{"url":"https://github.com/checkstyle/checkstyle/releases/tag/checkstyle-13.3.0","date":"2026-02-28T17:36:40Z","type":"stable","version":"checkstyle-13.3.0"},{"url":"https://github.com/checkstyle/checkstyle/releases/tag/checkstyle-13.2.0","date":"2026-02-05T20:28:40Z","type":"stable","version":"checkstyle-13.2.0"},{"url":"https://github.com/checkstyle/checkstyle/releases/tag/checkstyle-13.1.0","date":"2026-01-31T17:26:20Z","type":"stable","version":"checkstyle-13.1.0"},{"url":"https://github.com/checkstyle/checkstyle/releases/tag/checkstyle-13.0.0","date":"2026-01-04T23:48:39Z","type":"stable","version":"checkstyle-13.0.0"},{"url":"https://github.com/checkstyle/checkstyle/releases/tag/checkstyle-12.3.1","date":"2025-12-31T15:42:54Z","type":"stable","version":"checkstyle-12.3.1"},{"url":"https://github.com/checkstyle/checkstyle/releases/tag/checkstyle-12.3.0","date":"2025-12-13T15:50:49Z","type":"stable","version":"checkstyle-12.3.0"}]` | - |
| reliability.status_page | yes | - |
| security.scorecard | 7 | 5 |
| security.vulnerabilities | `{"count":2,"source":"https://advisories.ecosyste.ms/api/v1/advisories?ecosystem=maven&package_name=com.puppycrawl.tools%3Acheckstyle&per_page=100","last_12m":0,"max_severity":"MODERATE"}` | `{"count":0,"source":"https://advisories.ecosyste.ms/api/v1/advisories?ecosystem=pypi&package_name=flake8&per_page=100","last_12m":0,"max_severity":null}` |

## Capabilities (Code Quality Tools)

| Capability | Checkstyle | flake8 |
|---|:--:|:--:|
| **Core** |  |  |
| Function | Static analyzer | Linter |
| Language scope | Single-language | Single-language |
| Implementation language | Java | Python |
| **Capability** |  |  |
| Autofix | ✗ | ✗ |
| **Config** |  |  |
| Config model | Config file | Config file |
| **Extensibility** |  |  |
| Custom rules | ✓ | ✓ |
| **Deployment** |  |  |
| Deployment | CLI-local | CLI-local |
| **Delivery** |  |  |
| Editor integration | ✓ | ✓ |
| CI / VCS gating | ✓ | ✓ |
| **Insight** |  |  |
| Code metrics | ✓ | ✓ |
| **Performance** |  |  |
| Incremental / monorepo aware | - | - |
| **Licensing** |  |  |
| Open-source | OSS | OSS |
| **Commercial** |  |  |
| Pricing model | Free | Free |

*Source: vioscaleAI. Generated 2026-10-16T19:52:15.085Z. "-" = undocumented, not absent.*