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
- Parse TOML and emit clean, normalised output
- Supports tables `[section]`, arrays-of-tables `[[section]]`, inline tables, nested arrays
- TOML number formats: decimal, hex (`0x`), octal (`0o`), binary (`0b`), with underscore digit separators (`1_000_000`)
- Dates / times: TOML date / time / datetime literals
- Hand-rolled parser — most valid TOML works; very exotic edge cases may need a full library
How to use
- Paste your TOML content in the input panel.
- Click Format & Validate.
- Switch between TOML and JSON output tabs.
- Copy the result using the Copy button.
Tips & Best Practices
- Underscore digit separators (e.g. `1_000_000`) are valid TOML and now parse correctly.
- Inline tables like `point = { x = 1, y = 2 }` are supported; nest them at most 1-2 deep for readability.
- Arrays-of-tables (`[[products]]`) are the canonical pattern for repeating sections like config arrays.
- For very large / complex TOML, validate with `taplo` or `@iarna/toml` in your build pipeline.
- Strings can be basic (`"..."`), literal (`'...'`), multi-line basic (`"""..."""`), or multi-line literal (`'''...'''`).
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.