Checkstyle
Metrics as of , from the GitHub or GitLab API of each repository. Refreshed monthly.
What Checkstyle is
Checkstyle is a static analysis tool that checks Java source code against a coding standard. Its checks cover naming, imports, formatting, Javadoc, spacing and class design. Rules are selected and tuned in an XML configuration file. The project ships ready-made configurations for Google Java Style and Sun Conventions. It runs from the command line as an executable JAR and reports each violation with file, line and column. Ant tasks, Maven and Gradle plugins, and IDE integrations for Eclipse, IntelliJ IDEA, NetBeans and VS Code also run it. Releases are published on GitHub and Maven Central.
Written from the project's README, read , and its documentation (see sources).
- Category
- Code quality and static analysis
- License
- LGPL-2.1
- Language
- Java
- Changelog
- Releases on GitHub
Repository metrics
Status
activeLast commit within 90 days of the fetch date.Computed from the last commit date and the archive flag on the fetch date. See the status rules.
Alternatives
Listed code quality and static analysis tools, same primary language first, then by GitHub stars. Each line gives one fact from the tool's documentation where it differs from Checkstyle's, with its source.
SonarQube: Languages or files analysed: Java, JavaScript, TypeScript, Python, C#, Go, PHP, Kotlin and other language pages; IaC files such as Docker, Kubernetes, Terraform. source: Docs: Supported languages
SpotBugs: Languages or files analysed: Java programs. source: Docs: Introduction
Ruff: Languages or files analysed: Python files (*.py, *.pyi), Jupyter Notebooks (*.ipynb) and pyproject.toml. source: Docs: Configuring Ruff
ShellCheck: Languages or files analysed: Shell scripts in the sh, bash, dash, ksh and BusyBox dialects. source: Docs: shellcheck(1) manual
ESLint: Languages or files analysed: ECMAScript/JavaScript code; JSX parsing when enabled. source: README
mypy: Languages or files analysed: Python programs with type hints. source: README
golangci-lint: Languages or files analysed: Go code. source: README
Semgrep: Languages or files analysed: Community supported in Semgrep CE: C/C++, C#, Go, Java, JavaScript, TypeScript, Kotlin, Python, Ruby, Rust, PHP, Scala, Swift, Terraform. source: Docs: Supported languages for Semgrep Community Edition (CE)
Questions
Is Checkstyle open source?
Yes. Checkstyle is released under LGPL-2.1, an OSI-approved license, as reported by the GitHub API on 2026-09-22.
Is Checkstyle maintained?
On 2026-09-22, the last commit to the default branch was on 2026-09-22, so the listed status is active. Rule: Last commit within 90 days of the fetch date.
How many GitHub stars does Checkstyle have?
9,571 stars on 2026-09-22, from the GitHub API. The number is refreshed at each monthly update.
What language is Checkstyle written in?
The repository's primary language, as reported by the GitHub API, is Java.
Sources
- GitHub REST API: repository, read
- GitHub REST API: commits, read
- GitHub REST API: latest release, read
- GitHub REST API: contributors, read
- README, read
- Checkstyle website (checkstyle.org), read