JSON to TOML
ConverterConvert JSON to TOML config format with nested tables, arrays and typed values for Rust, Python and other project configuration file generation.
About JSON to TOML
TOML (Tom's Obvious Minimal Language) is known for clear semantics and is the standard config format for modern toolchains like Rust's Cargo and Python's pyproject.toml. This tool converts JSON to TOML locally in your browser, correctly handling tables, arrays of tables, inline tables, and scalar types. Your data never leaves your device. Tip: Bookmark this tool for quick access whenever you need format conversion. All processing happens locally in your browser — no data upload, so feel free to paste sensitive content.
How to Use
- Open the JSON to TOML tool page
- Enter or paste your data into the input area
- View the real-time results and use the copy button to get the output
Use Cases
- Generate Cargo config — Turn a JSON dependency list into the [dependencies] section of Cargo.toml.
- Migrate Python projects — Convert JSON-style metadata from setup.py into the TOML structure pyproject.toml needs.
- Unify config format — When a team standardizes on TOML, batch-convert legacy JSON configs.
- Understand TOML tables — Use JSON↔TOML side by side to grasp nested tables and arrays of tables.
- Toolchain integration — Convert API JSON to TOML for tools like Hugo or Netlify to read.
- Config templating — Convert a JSON template from a config generator into TOML for a project that uses pyproject.toml.
- Cross-language sharing — Export a JSON schema as TOML so a Rust and Python project share the same config structure.
FAQ
How is JSON null converted?
TOML has no null type. Keys with null values are skipped because TOML cannot represent emptiness — note these keys disappear after conversion.
What do nested object arrays become?
Arrays of objects become TOML's "array of tables" syntax [[table]], the standard way TOML expresses repeated structures.
Is deep nesting supported?
Yes, but TOML readability suffers with very deep nesting. Beyond 3-4 levels, consider splitting the config.
How are date-times handled?
Dates in JSON are usually strings and stay strings in TOML. TOML's native date types require RFC 3339 format to be recognized.
Need the reverse?
Use our TOML to JSON tool.
Any browser compatibility requirements?
This tool works in all modern browsers (Chrome, Firefox, Edge, Safari). No plugins or extensions required.
Can I use it offline?
After initial load, most features work offline. The core logic runs entirely in your browser with no network dependency.
Comments
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