100% local — your data never leaves your browser

JSON to TOML Converter — Free Online Tool

Convert JSON to TOML instantly in your browser. Free, private and offline-friendly: your data never leaves your device.

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Swap: TOML → JSON

JSON input

TOML output

Why convert JSON to TOML?

You are migrating configuration to a tool that speaks TOML — Cargo, Poetry, Netlify — and your current config is JSON. Paste it above and get idiomatic TOML with proper tables and arrays of tables, ready to commit.

How it works

The converter parses your JSON locally and writes TOML 1.0: nested objects become tables, arrays of objects become arrays of tables, and strings are quoted and escaped per the specification. JSON that cannot be represented (null values, non-object root) is rejected with an error instead of being silently altered.

Frequently asked questions

Is my JSON data uploaded to a server?
No. The conversion runs entirely in your browser with JavaScript. Nothing is sent over the network, which makes the tool safe for sensitive data.
What JSON can be represented in TOML?
The root must be an object, and TOML has no null. Rather than silently dropping null values, the converter reports an error so you never lose data unnoticed.
How are nested objects and arrays written?
Nested objects become TOML tables ([section]) and arrays of objects become arrays of tables ([[section]]), the idiomatic TOML layout.

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