How are nested objects and arrays converted?

Nested objects become [table] headers using dotted paths, and arrays of objects become [[array of tables]] entries. Arrays of scalars are written inline, e.g. tags = ["fast", "free"].

How accurate is the conversion?

The output targets the TOML v1.0.0 syntax. Strings are escaped with basic-string quoting and keys that aren't bare-key safe are quoted. JSON null has no TOML equivalent, so it is written as an empty string to keep the file valid.

Is my JSON uploaded anywhere?

No. The conversion runs entirely in your browser with JavaScript — your config and data are never sent to a server or stored.

JSON to TOML Converter

Convert JSON to TOML in your browser

TOML is the config format behind Cargo.toml, pyproject.toml and many other tools, but data often arrives as JSON. This converter turns a valid JSON object into clean TOML that targets the TOML v1.0.0 syntax, so you can paste it straight into a config file.

How it works

The converter maps each JSON construct to its TOML equivalent:

JSON	TOML
nested object	`[table]` header with dotted path
array of objects	`[[array of tables]]` entries
array of scalars	inline array, e.g. `tags = ["a", "b"]`
string	basic-string quoting with escapes
number / boolean	written as-is
null	empty string (TOML has no null)

Keys that are not bare-key safe (containing spaces or special characters) are quoted automatically. TOML requires an object at the top level, so the input must be a JSON object.

Example

This JSON:

{ "name": "demo", "deps": { "serde": "1.0" }, "tags": ["fast", "free"] }

becomes:

name = "demo"
tags = ["fast", "free"]

[deps]
serde = "1.0"

The scalar array stayed inline, and the nested deps object became a [deps] table. The conversion happens entirely in your browser — your config is never uploaded or stored.