Convert JSON to TOML Online Free
Convert JSON data into clean, readable TOML configuration files. Ideal for creating Cargo.toml, pyproject.toml, or any TOML config from existing JSON data.
To convert JSON to TOML, drop your .json file onto the converter. JSON objects become TOML tables, arrays become TOML arrays, and all primitive types are mapped to their TOML equivalents. Runs entirely in your browser.
Convert JSON to TOML
Drop your JSON file here to convert it instantly
Drag & drop your .json file here, or click to browse
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JSON vs TOML: Format Comparison
Key differences between the two formats
When to Convert
Common scenarios where this conversion is useful
Creating Rust Cargo.toml from JSON
Generate Cargo.toml files for Rust projects from JSON package metadata, dependency lists, or build configuration data.
Python pyproject.toml generation
Convert JSON project metadata into pyproject.toml format for Python packaging with setuptools, Poetry, or Flit.
Static site generator configs
Create TOML configuration files for Hugo, Netlify, or other tools that prefer TOML over JSON for their settings.
Making configs human-editable
Convert JSON configs to TOML when you want a format that is easier for humans to read and edit by hand, with support for inline comments.
How to Convert JSON to TOML
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1
Upload your JSON file
Drag and drop your .json file onto the converter, or click to browse. Any valid JSON object is accepted.
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2
Automatic conversion
JSON objects become TOML tables, arrays become TOML arrays, and primitive values are mapped to TOML key-value pairs.
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3
Download the TOML result
Click Download to save your .toml file. The output uses clean formatting with section headers and proper value quoting.
Frequently Asked Questions
Nested objects become TOML table sections. For example, {"database": {"host": "localhost"}} becomes [database] followed by host = "localhost" on the next line.
TOML does not support null values. JSON null values are omitted from the TOML output. If null values are important, consider using YAML instead.
Arrays of objects become TOML arrays of tables, using the [[double.bracket]] syntax. Each object in the array becomes a separate [[section]].
Yes. JSON integers map to TOML integers, and floating-point numbers map to TOML floats. Very large integers that exceed TOML's 64-bit range will need manual adjustment.
The converter does not add comments automatically, but since TOML supports comments with #, you can freely add them to the downloaded file.
Yes. The generated TOML follows the TOML v1.0 specification and is compatible with all standard TOML parsers.
JSON true and false map directly to TOML true and false. No conversion issues with booleans.
JSON keys containing dots are quoted in the TOML output to prevent them from being interpreted as nested table paths.
Largely yes, except for JSON null values which are dropped. Converting the TOML back to JSON will produce equivalent data.
Yes. The entire conversion happens in your browser. No data leaves your device.
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