Free Rust Formatter & Validator

Format, beautify, and validate your Rust code. Check for syntax errors and get clean, readable Rust code following community style.

Input Rust Code

Results

Status
Ready to format or validate

Formatted / Validated Rust

// Formatted output will appear here

How To Use Rust Formatter & Validator

📝 Step 1: Enter Rust Code

Paste your Rust code in the input area. Supports multiple items, functions, structs, and macros.

⚙️ Step 2: Choose Rust Edition

Select your Rust edition (2015, 2018, or 2021) for accurate formatting and validation.

🔧 Step 3: Format or Validate

Click "Format Rust" to beautify your code with proper indentation and spacing. Click "Validate Rust" to check for syntax errors.

📋 Step 4: Copy or Download

Use the "Copy" button to copy formatted Rust to clipboard, or "Download" to save as .rs file.

💡 Pro Tips

✓ Use the Sample button to load an example Rust program.

✓ Validation checks for: missing semicolons, unmatched braces, invalid attributes, incorrect macro usage.

✓ Formatting follows official Rust style guidelines (rustfmt).

✓ Works with complex code including generics, lifetimes, and closures.

🔍 Example

// Before formatting: fn main(){let x=5;let y=6;println!("Sum: {}",x+y);} // After formatting: fn main() { let x = 5; let y = 6; println!("Sum: {}", x + y); }

Frequently Asked Questions

What Rust editions are supported?
We support Rust 2015, 2018, and 2021 editions. Each edition has its own syntax rules (e.g., async/await in 2018+, new keywords).
Does it validate all Rust syntax?
The validator checks for common syntax errors including: missing semicolons, unmatched braces/parentheses, invalid attributes, incorrect macro invocation, and basic type errors. It's designed for everyday Rust development.
What formatting options are available?
The formatter adds proper indentation, line breaks, spaces around operators, and organizes imports (basic). It follows the official Rust style guide (rustfmt defaults). Comments and string literals are preserved.
Can I format multiple Rust items?
Yes! The tool handles multiple functions, structs, enums, modules, and even entire files. Each item is formatted independently while maintaining overall readability.
Is my Rust code secure?
Absolutely. All processing happens in your browser with PHP only serving the page. Your code is never sent to our servers. It's completely client-side for privacy and security.
What are common Rust errors it detects?
Common errors include: missing semicolons, unmatched angle brackets in generics, incorrect lifetime syntax, missing 'fn' keyword, invalid attribute syntax, and macro errors.
Does it work with macros and attributes?
Yes, basic macro invocations (println!, vec!, etc.) and attributes (#[derive(Debug)]) are supported. Custom macros may not be fully validated but will be formatted.
How accurate is the validation?
The validator catches most syntax errors but may not catch type mismatches or borrow checker issues (since it doesn't run the compiler). It's great for quick syntax checking and formatting.