TOML Formatter & Validator

Format, validate, and convert TOML — used in Rust (Cargo.toml), Python (pyproject.toml), and more

TOML Input

TOML Formatter & Validator

Format, validate, and convert TOML — used in Rust (Cargo.toml), Python (pyproject.toml), and more

Features

  • Format and validate TOML files instantly
  • Convert TOML to JSON with one click
  • Support for tables, arrays of tables, inline tables
  • Handles strings, numbers, booleans, dates, and arrays
  • Error messages with line numbers for invalid TOML
  • 100% client-side — no data sent to servers

How to use

  1. Paste your TOML content in the input panel.
  2. Click Format & Validate.
  3. Switch between TOML and JSON output tabs.
  4. Copy the result using the Copy button.

Tips & Best Practices

  • Use this tool to validate Cargo.toml or pyproject.toml before committing.
  • The JSON output is useful for debugging or converting to other formats.
  • Arrays of tables ([[section]]) are fully supported.

FAQ

What is TOML?

TOML (Tom's Obvious Minimal Language) is a configuration file format used by Rust (Cargo.toml), Python (pyproject.toml), Hugo, and many other tools.

Can it convert TOML to JSON?

Yes, click the JSON tab in the output panel to see the JSON equivalent of your TOML file.

Is my data private?

Yes, all processing happens in your browser. No configuration data is sent to any server.