TOML ↔ JSON Converter
Convert TOML to JSON and JSON to TOML entirely in your browser — no server, no upload required.
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What is TOML?
TOML (Tom's Obvious Minimal Language) is a configuration file format designed to be easy to read and write. It maps unambiguously to a hash table and is the standard format for Rust's Cargo.toml, Python's pyproject.toml, and the Hugo static site generator's configuration.
This tool converts between TOML and JSON formats in your browser.
How to convert TOML to JSON online
- Paste your TOML or JSON into the input panel.
- Select the conversion direction: TOML to JSON or JSON to TOML.
- The converted output appears instantly.
- Copy or download the result.
Frequently Asked Questions
What is the difference between TOML and YAML?
TOML is simpler and less ambiguous than YAML. YAML's indentation-based syntax has edge cases that cause parsing surprises. TOML has a more explicit type system and is easier to parse correctly.
What types does TOML support?
TOML supports: strings, integers, floats, booleans, datetime (RFC 3339), arrays, and tables (dictionaries). TOML datetimes are a type not directly representable in JSON.
Can every TOML document be converted to JSON?
Yes, with one exception: TOML datetime values are converted to ISO 8601 strings in JSON since JSON has no native date type.
Where is TOML used?
TOML is used in Rust (Cargo.toml for package configuration), Python (pyproject.toml for project metadata), Hugo, and many other modern tools that prioritise readable configuration files.