Java Code Checker
Check Java code for common bugs and bad practices: string ==, printStackTrace, raw types, empty catch blocks and high complexity. Free and private: runs in…
Paste Java code to find issues that compile fine but cause bugs in production, each with a line number and an explanation.
Runs entirely in your browser. Nothing you paste is uploaded or stored.
Use cases
- Check a function before opening a pull request.
- Explain a review comment with numbers instead of opinions.
- Find the riskiest code to refactor first.
Frequently asked questions
Does it compile my code?
No. It checks patterns statically, so it also works on partial snippets. Syntax errors are best caught by javac or your IDE.
Is the Java Code Checker free?
Yes. It is free with no sign-up, and it runs entirely in your browser, so your input is never uploaded or stored.
How accurate is a browser-based code check?
It uses fast heuristics on the snippet you paste, so it is great for quick feedback. For whole repositories, cross-file analysis and history, run a full CodeInspector scan.
Related tools
Checking one snippet is a start. Scan your whole repository for free with CodeInspector.