Java Formatter
FormattersFormat Java code with clang-format WASM using Google Java Style. Configurable indent, 100-column limit, method separation, and blank line insertion. Browser-based.
About Java Formatter
The Java Formatter is a clang-format WASM-powered, browser-based tool that instantly formats Java source code according to Google Java Style — the de-facto standard for modern Java projects. Using a WebAssembly port of clang-format run in a Web Worker, it applies configurable indent width, a 100-column line limit, and automatic blank-line insertion between method and field definitions (`SeparateDefinitionBlocks: Always`). The result is consistently structured code that matches the output of Google's style enforcement tools. Your code never leaves the browser.
Features
- ✓Powered by clang-format WASM — a WebAssembly port of the industry-standard C/C++/Java formatter
- ✓Uses Google Java Style (BasedOnStyle: Google) — the de-facto standard for Java
- ✓Configurable indent width: 2 spaces, 4 spaces, or tab
- ✓100-column line limit (Google Java Style default)
- ✓Automatic blank lines between method, field, and class definitions
- ✓Handles annotations (@Override, @SuppressWarnings, @FunctionalInterface)
- ✓Formats generics, lambdas, streams, and inner classes correctly
- ✓Web Worker execution — WASM runs off the main thread, UI stays responsive
- ✓Syntax-highlighted editor for both input and output
- ✓One-click clipboard copy of formatted output
- ✓Real-time byte-savings stats (input vs output size)
- ✓Language picker — instantly switch to C#, Python, Go, or 20+ other formatters
- ✓Mobile-responsive layout with a dedicated Format button
- ✓100% client-side — your code never leaves the browser
Common Use Cases
- Normalising Java class files to Google Java Style before committing to source control
- Formatting Java code snippets for documentation, Javadoc, or blog posts
- Cleaning up auto-generated Java classes from ORM tools or protobuf compilers
- Preparing readable Java for code reviews and pull requests
- Standardising formatting across a multi-module Maven or Gradle project
- Formatting Spring Boot controller, service, and repository classes
Frequently Asked Questions
QWhich Java style guide does this use?
Google Java Style (BasedOnStyle: Google in clang-format), which is the most widely adopted Java style guide and is used by Google's own open-source Java projects.
QDoes it support Java annotations and generics?
Yes — clang-format natively supports Java annotations (@Override, @Autowired, etc.), generic type parameters, lambda expressions, and stream API chains.
QWhy is clang-format used for Java instead of a Java-native formatter?
clang-format includes a Java mode and can be compiled to WebAssembly, making it the only production-quality Java formatter available in a browser environment without a JVM.
QIs my code sent to a server?
No. The clang-format WASM binary runs entirely inside your browser in a Web Worker. No code is transmitted to any server.