Convert JSON to TOML Online
Free, private JSON to TOML converter. Your files never leave your browser. All processing happens locally on your device.
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How to convert JSON to TOML
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Once the conversion finishes, click the download button and you are done. The converted file is ready to use.
Why convert JSON to TOML?
JSON and TOML serve different purposes. Converting between them lets you use whichever format works best for your situation.
What is a JSON file?
JavaScript Object Notation: JSON is the standard format for exchanging data between web applications. APIs, config files, and data storage all use it. The format is simple enough to read by eye but structured enough for machines to parse.
Created by: Douglas Crockford, popularized in the early 2000s
Used for: APIs, configuration files, data exchange, web applications, NoSQL databases
Technical details: Text-based format supporting objects, arrays, strings, numbers, booleans, and null. No comments in standard JSON. Nested structures allowed.
Compatibility: Every programming language has a JSON parser. All modern web APIs use it.
What is a TOML file?
Tom's Obvious, Minimal Language: TOML is a configuration format designed to be easy to read. It looks similar to INI files but supports nested tables and typed values. Rust's Cargo and Python's pyproject.toml use it.
Created by: Tom Preston-Werner (GitHub co-founder), first released in 2013
Used for: Configuration files (Cargo.toml, pyproject.toml), application settings
Technical details: Key-value pairs with sections (tables). Supports strings, integers, floats, booleans, dates, arrays, and nested tables. Minimal syntax.
Compatibility: Supported by most modern programming languages via libraries. Common in Rust and Python ecosystems.
JSON vs TOML
| Feature | JSON | TOML |
|---|---|---|
| Type | JavaScript Object Notation | Tom's Obvious, Minimal Language |
| Best for | APIs, configuration files, data exchange, web applications, NoSQL databases | Configuration files (Cargo.toml, pyproject.toml), application settings |
| Compatibility | Every programming language has a JSON parser. All modern web APIs use it. | Supported by most modern programming languages via libraries. Common in Rust and Python ecosystems. |
| Pros | Human-readable, universal in web development, supports nested data | Very readable, explicit types, less error-prone than YAML |
| Cons | No comments, no date type, verbose for large datasets compared to binary formats | Less common than JSON or YAML, deeply nested data gets awkward |