Checkstyle vs Flake8
Checkstyle
checkstyle.orgFlake8
flake8.pycqa.orgSide by side
| Figure | Checkstyle | Flake8 |
|---|---|---|
| Price from | Free | Free |
| Free plan | Yes | Yes |
| Free trial | — | — |
| Open source | — | Yes |
| Windows | Yes | Yes |
| macOS | Yes | Yes |
| Linux | Yes | Yes |
| API | — | Yes |
| Self-hosted | — | Yes |
| Plans published | 1 | 2 |
| Spec score · Linters | 8.0 (#9) | 8.8 (#2) |
| Configuration | Users can choose supplied Google Java Style, Sun Conventions, OpenJDK Style, or Doc Style configurations, or create their own. | Project configuration can be stored in setup.cfg, tox.ini, or .flake8 using INI format. |
| Purpose | Checkstyle analyzes Java source code against configurable rules to help teams enforce coding standards. | Flake8 combines pycodestyle, pyflakes, McCabe, and third-party plugins to check Python code style and quality. |
Plans
In their own words
Checkstyle
Checkstyle is a free Java source-code analyzer for programmers who follow a coding standard. It checks naming, imports, Javadoc, formatting, class design, and coding practices against configurable rules. You can select supplied Google Java Style, Sun Conventions, OpenJDK Style, or Doc Style configurations, or create your own. Checkstyle runs from its command-line tool or as an Ant task, with documented Maven and Gradle integrations. Listed IDE and CI integrations include Eclipse, Bamboo, GitHub Actions, Codacy, and Code Climate. It runs on Linux, macOS, and Windows. The current site says it parses Java features through Java 25; versions 13.x and 14.x require Java runtime 21 or newer. Analysis is single-file and source-level, without expression-type determination or a full inheritance hierarchy. Releases are available through GitHub releases and Maven Central, including a standalone all-in-one JAR. It is licensed under LGPL-2.1-or-later and supports only the latest version.