About This TOML Formatter & Validator
Our free TOML formatter and validator tool helps you validate and format TOML configuration files with instant error detection. Whether you're working with Cargo.toml for Rust projects, pyproject.toml for Python, or any other TOML config file, this tool provides syntax validation with line-specific error reporting. All processing happens securely in your browser without any server communication, ensuring your configuration data stays private.
Features
Validate TOML syntax with detailed error messages
Format TOML with customizable indentation (2 or 4 spaces)
Error detection with line numbers
Check section headers [section] and [[table-arrays]]
Validate key-value pairs
Detect unmatched quotes
Add proper spacing between sections
Real-time character and line count
One-click copy to clipboard
All processing done client-side for privacy
Benefits
Fast and instant validation
Detailed error reporting with exact line numbers
Privacy-focused - no server uploads
Works completely offline
No file size limits
Free with unlimited use
No registration required
Mobile-friendly interface
Safe for sensitive configuration files
Helps learn TOML syntax
Common Use Cases
Validating Rust Cargo.toml files
Formatting Python pyproject.toml files
Checking configuration files for web applications
Validating Hugo site config.toml files
Debugging TOML syntax errors
Formatting package manager configs
Learning TOML structure and syntax
Standardizing TOML formatting across projects
Verifying TOML before deployment
Cleaning up messy TOML data