JSON to TOML Converter — Free Online

Paste JSON data to convert it into clean, human-readable TOML configuration format. Runs entirely in your browser — nothing is uploaded.

JSON Input — paste, type, or drop a file

📄 Drop a .json file here, or browse

TOML Output

What This Tool Does

The JSON to TOML converter takes JSON data and transforms it into clean, idiomatic TOML format. This is useful when you need to create configuration files for Rust projects (Cargo.toml), Python packaging (pyproject.toml), Hugo sites, or any tool that uses TOML as its configuration format.

The converter handles both JSON objects (converted to TOML tables) and JSON arrays of objects (converted to TOML arrays of tables using [[double.bracket]] syntax).

When to Convert JSON to TOML

Creating config files — converting API responses or data structures into TOML configuration files
Rust projects — generating Cargo.toml from build metadata stored as JSON
Python packaging — creating pyproject.toml from JSON-based package metadata
Human readability — TOML is easier for humans to read and edit than JSON for configuration
Adding comments — convert to TOML first, then add comments (which JSON does not support)

Privacy & Security

All JSON parsing and TOML generation runs locally in your browser using JavaScript. No data is sent to any server.

💡 Need to go the other direction? Use the TOML to JSON converter to parse TOML into JSON. You can also convert between JSON and YAML.

Related Guides & Tutorials

Guide

TOML ↔ JSON: Complete Guide

Conversion rules, typing details, and real-world examples.

Tool

⇄ TOML to JSON

Convert TOML config files to JSON format.

Tool

JSON to YAML

Convert JSON to YAML config format.

Frequently Asked Questions

Can JSON represent all TOML features?▼

JSON can represent all TOML data values, but TOML-specific features like comments, native datetime types, and section-based organization are lost.

Does this converter handle deeply nested JSON?▼

Yes. The converter flattens deeply nested JSON objects into TOML table sections using dotted paths, producing clean, idiomatic TOML output.

What happens to JSON null values?▼

TOML has no null type. JSON null values are converted to empty strings in the TOML output, since TOML requires all keys to have a defined value.

Can I convert a JSON array?▼

Yes. If the top-level JSON is an array of objects, the converter wraps them using TOML's [[items]] array-of-tables syntax. Arrays of primitives are converted to a top-level items key.

Can I go from TOML back to JSON?▼

Yes — use the TOML to JSON converter tool to parse TOML files and get formatted JSON output.