About TOML Formatter

Format and validate TOML configuration files. Part of the DevTools Surf developer suite. Browse more tools in the Text / String collection.

Use Cases

• Formatting Cargo.toml files for consistent Rust project style
• Validating pyproject.toml before publishing Python packages
• Cleaning up Hugo static site configuration files
• Standardizing Netlify or Cloudflare Pages deployment configs

Tips

• Format Cargo.toml files for consistent Rust project configs
• Validate TOML syntax to catch missing brackets or quotes
• Use this to clean up pyproject.toml before committing changes

Fun Facts

• TOML was created by Tom Preston-Werner (GitHub co-founder) in 2013; the name stands for 'Tom's Obvious, Minimal Language.'
• TOML 1.0.0 was finally released on January 12, 2021, after 8 years of development and community feedback.
• Rust's Cargo package manager adopted TOML for its manifest format (Cargo.toml) in 2014, making it the language's de facto config format.

FAQ

Does it validate as well as format?

Yes — parse errors are reported with line/column. The formatter won't output invalid TOML; if input is malformed, you get the original back with an error.

What style conventions?

Inline tables on single lines; array-of-tables indented; multi-line strings with triple-quote markers. Matches the TOML spec examples.

Does it alphabetize keys?

Off by default (TOML is order-sensitive for ergonomic grouping). Toggle on for deterministic output — useful for lockfile-like files where diffs matter.

What TOML version does it target?

TOML 1.0.0 — the current spec. All 1.0 features supported: inline tables, arrays of tables, dotted keys, multi-line strings.