How to use this developer tool
- Paste Rust source code.
- Choose a formatting style and indent size.
- Select cleanup options and click Format Rust.
- Review the formatted output and changed-line summary before copying or downloading.
#171 · Programming Language Tools Developer Tool
Rust Formatter
Format Rust source code in your browser with indentation, spacing, blank-line cleanup, and a clear change summary. Raw strings, comments, and common macro content are protected where possible, but rustfmt remains the final authority.
Developer Input
Browser-based processingspaces
Ad space
What this developer tool does
This Rust formatter applies conservative whitespace and indentation normalization without compiling the source. It reports changed lines and avoids rewriting ownership, lifetimes, expressions, or program behavior.
Protect strings and comments → normalize braces and whitespace → indent by block depth → compare changed lines → report processing time.
Run rustfmt before committing production Rust code, especially when macros, complex generics, or unusual attributes are present.
Example
The page loads a working Rust Formatter example. Run the tool to compare the sample input with the generated output and status summary.
Tips for better output
- Start with valid, isolated code or data.
- Review heuristic and inferred results manually.
- Use the official compiler, formatter, linter, or IDE before production use.
FAQ
How do I format Rust code online without installing rustfmt?
Paste the Rust source, choose the formatting options, and run the formatter. The result is browser-based and should still be checked with rustfmt.
How can I compare Rust code before and after formatting?
The output summary reports changed lines and the formatted code remains separate from the original input.
Does the formatter preserve Rust raw strings and macros?
It protects common strings and comments and applies conservative formatting, but complex macro syntax should be verified manually.
Can this browser tool replace the official compiler or IDE inspection?
No. It performs browser-based formatting, conversion, structural parsing, or heuristic analysis. Always verify production code with the official toolchain.
Does this tool upload my source code?
No processing is implemented by the page itself in your browser. Review your hosting and analytics configuration separately if you add external services.
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Tool coverage
| Module | Coverage |
|---|---|
| Formatting | Indentation, braces, spacing |
| Safety | No semantic code rewrites |
| Verification | Use rustfmt for final output |