TOML ↔ JSON Converter

Convert TOML to JSON or JSON to TOML instantly. Supports tables, arrays of tables, inline tables, and all TOML value types. 100% client-side.

Last reviewed: April 2026
Reviewed by , software engineer · last updated April 2026

New to this tool? Click here for instructions

TOML Input
JSON Output
Paste TOML or JSON above to convert.

How to Use the TOML to JSON Converter

To use the TOML to JSON Converter, follow these steps:

1. Choose the conversion direction ("TOML to JSON" or "JSON to TOML").

2. Paste your TOML or JSON data into the input area.

3. The conversion happens as you type, and the result will be displayed on the right side.

4. Copy or download the output as a .json or .toml file.

When to Use the Tool in Real Workflows

Use the TOML to JSON Converter when you need to convert configuration files between TOML and JSON formats. This is particularly useful when working with tools that require one format but you have the other. For example, if you have a Rust project with a Cargo.toml file and need to analyze it as JSON, or if you have a JSON representation of a configuration and need to convert it back to TOML.

How It Works

The TOML to JSON Converter uses a client-side approach, meaning all processing happens in your browser. This ensures that your data is never sent to a server, maintaining your privacy and security. When you paste your data into the input area, the converter uses a JavaScript library to parse the input and convert it to the desired format. The result is then displayed on the right side of the page.

Tips, Edge Cases, or Limitations

1. Client-Side Processing: All data is processed in your browser, so your data remains private and secure.

2. Supported Formats: The converter supports the core TOML specification, including sections, arrays, inline tables, booleans, integers, floats, and multi-line strings.

3. Real-Time Conversion: The conversion happens as you type, making it quick and convenient.

4. Download Options: You can easily download the output as a .json or .toml file for further use.

Frequently Asked Questions

TOML (Tom's Obvious Minimal Language) is a configuration file format designed to be easy to read due to its simple and unambiguous semantics. It maps to a hash table and is used in many tools including Rust's Cargo.toml, Python's pyproject.toml, Hugo static site generator, and many other developer tools.
[section] creates a nested object, while [[array]] appends objects to an array. This allows you to define lists of configurations without verbose array syntax.
TOML is used as the standard configuration format in many developer tools, including Rust (Cargo.toml), Python packaging (pyproject.toml), Hugo (config.toml), and many other developer tools.
This converter supports the core TOML specification, including key = "value" pairs, arrays, inline tables, booleans, integers, floats, and multi-line strings.
No, your data is processed entirely in your browser. The converter does not send any data to a server, ensuring your privacy and security.

Quick reference

TOML ↔ JSON Converter Quick Reference
TOML Key JSON Key TOML Value JSON Value
name name "Alice" "Alice"
age age 30 30
tags tags - "python" ["python"]
settings settings title = "default" {"title": "default"}
inline inline key = {value = 42} {"key": {"value": 42}}
enabled enabled true true