TOML Formatter & Validator

Format, validate, and minify TOML files with syntax highlighting and error reporting. All processing happens in your browser.

How It Works

This tool parses your TOML input using a client-side parser that follows the TOML v1.0.0 specification. All processing happens entirely in your browser — no data is sent to any server.

• Format — parses and re-serializes TOML with consistent indentation and spacing
• Minify — removes comments and unnecessary whitespace to produce compact output
• Validate — checks syntax and reports the exact error position if invalid
• Sort Keys — alphabetically sorts keys within each table section
• Syntax Highlighting — color-codes tables, keys, strings, numbers, booleans, and dates

About TOML

TOML (Tom's Obvious Minimal Language) is a configuration file format that is easy to read due to its clear semantics. It is designed to map unambiguously to a hash table and is used by tools like Cargo (Rust), Poetry (Python), and Hugo.

TOML Syntax Rules

• Key/value pairs: key = "value"
• Tables (sections): [table]
• Array of tables: [[array]]
• Strings: basic "hello" or literal 'hello'
• Numbers: integers 42, floats 3.14, hex 0xDEAD
• Booleans: true or false
• Dates: 1979-05-27T07:32:00Z
• Inline tables: { key = "value" }
• Arrays: [1, 2, 3]
• Comments start with #

Common Use Cases

• Rust/Cargo — Cargo.toml defines package metadata and dependencies
• Python — pyproject.toml for project configuration (PEP 518)
• Hugo — static site generator configuration files
• Git — .gitconfig uses a TOML-like format
• CI/CD — various pipeline configurations use TOML