How to use this developer tool
- Paste Java source.
- Choose a brace style and indentation width.
- Select cleanup options.
- Run Format Java.
- Review, copy, or download the .java output.
#139 · Programming Languages Developer Tool
Java Formatter
Format Java source by normalizing indentation, brace placement, operator spacing, blank lines, trailing whitespace, and line endings. Strings, character literals, comments, and text blocks are protected during browser-based formatting.
Developer Input
Source codespaces
Ad space
What this developer tool does
It applies deterministic whitespace formatting while masking literals and comments. It does not compile or alter identifiers.
Protect literals → normalize braces and newlines → calculate depth → clean spaces → restore protected text → compare output.
This formatter is heuristic. Compile and test the output, especially when source contains unusual constructs or text blocks.
Example
Input
public class Test
{
public void run(){}Output
public class Test {
public void run() {}
}Tips for better output
- Use Java Standard for conventional projects.
- Preserve comments and text blocks.
- Compile after formatting generated or unusual code.
FAQ
How do I format Java code online?
Paste Java code, select a brace style and indentation width, then run the formatter.
How can I convert Java Allman braces to K&R style?
Choose K&R or Java Standard and format the source.
How do I replace Java tabs with four spaces?
Set the indent size to four; leading indentation is normalized.
Can I remove trailing whitespace from Java code?
Yes. Keep Remove trailing whitespace enabled.
Does formatting Java code change program behavior?
Whitespace normally does not, but heuristic formatting should still be compiled and tested.
Related developer tools
Formatting options
| Braces | Java Standard, K&R, Allman |
|---|---|
| Indentation | 2 or 4 spaces |
| Protection | Strings, comments, text blocks |
| Output | .java |