TOML (Tom's Obvious Minimal Language) is a minimal config file format that's easy to read. It's used in Rust's Cargo.toml, Python's pyproject.toml, Hugo, and many other tools.
Nested JSON objects are converted to TOML [section] and [[array]] headers, the idiomatic TOML way.
Numbers, booleans, null, strings, arrays and nested tables are all mapped to their correct TOML equivalents with proper quoting rules applied.
Export the result as a .toml file ready to drop into your Rust, Python, Go, or Hugo project.
JSON is a general-purpose data interchange format. TOML is designed specifically for configuration files — it's more human-readable, supports comments, and uses section headers instead of deeply nested braces.
Arrays of primitives become TOML inline arrays. Arrays of objects become TOML array-of-tables using the [[table]] syntax.
TOML has no native null type. JSON null values are converted to the empty string "" and flagged with a comment so you can handle them appropriately.
TOML is used by Rust (Cargo.toml), Python packaging (pyproject.toml), the Hugo static site generator, the uv package manager, Gitea, and many other developer tools.