ToolBox.Online

TOML Formatter - Free Online TOML Beautifier

Format and beautify TOML configuration files online. Clean up messy TOML with proper indentation and structure.

What is TOML Formatter?

TOML (Tom's Obvious Minimal Language) is a configuration file format designed to be easy to read and write. Created by Tom Preston-Werner (co-founder of GitHub), TOML maps clearly to a hash table and is used as the configuration format for many popular tools and frameworks. You will find TOML files in Rust projects (Cargo.toml), Python projects (pyproject.toml), Hugo static sites (config.toml), Netlify deployments (netlify.toml), and many other tools. The format supports strings, integers, floats, booleans, dates, arrays, and tables (sections). A TOML formatter cleans up inconsistent spacing, aligns equals signs, organizes sections logically, and ensures your configuration files are readable and maintainable. This is especially useful when multiple team members edit the same configuration file with different formatting habits.

How to Use TOML Formatter

Paste your TOML content into the input area. Click "Format" to beautify the output with proper indentation, consistent spacing around equals signs, and organized sections. The formatter preserves all your values and structure while making the file clean and readable. Copy the result with one click.

How TOML Formatter Works

The TOML formatter processes your input by: • Ensuring consistent spacing around equals signs (key = value) • Organizing top-level key-value pairs before table sections • Adding blank lines between table sections ([section]) for readability • Preserving inline tables and arrays in their compact form when short • Breaking long arrays across multiple lines with proper indentation • Maintaining the order of keys and sections as written • Preserving comments in their relative positions The formatter does not reorder your keys or sections — it respects your original organization while making the formatting consistent throughout the file.

Common Use Cases

  • Cleaning up Cargo.toml files in Rust projects after adding multiple dependencies
  • Formatting pyproject.toml for Python projects to ensure consistent style
  • Beautifying Hugo or Netlify configuration files for readability
  • Standardizing TOML formatting before committing to version control
  • Making configuration files readable for code reviews
  • Organizing messy TOML files that have grown over time with inconsistent formatting

Frequently Asked Questions

What is TOML?

TOML (Tom's Obvious Minimal Language) is a configuration file format that is easy to read due to its clear semantics. It is commonly used in Rust (Cargo.toml), Python (pyproject.toml), Hugo, Netlify, and many other projects and tools.

Does this formatter validate TOML?

This tool formats valid TOML content. If your input has syntax errors, the formatter will attempt to preserve the structure as closely as possible, but the output may not be valid TOML until the errors are fixed.

How is TOML different from JSON or YAML?

TOML is designed specifically for configuration files. Unlike JSON, it supports comments and has a more human-friendly syntax. Unlike YAML, it has no significant whitespace issues and is less error-prone for configuration use cases.

Does it support nested tables and arrays of tables?

Yes. The formatter correctly handles nested tables ([parent.child]), arrays of tables ([[array]]), inline tables, and all other TOML data structures.

Will it change the order of my keys?

No. The formatter preserves the original order of all keys, tables, and sections. It only changes the formatting (spacing, indentation, line breaks), not the structure or order of your content.

Can I format partial TOML snippets?

Yes. You can paste a partial TOML file (such as a single section or a few key-value pairs) and the formatter will clean it up. It does not require a complete, valid TOML document.

Related Tools