About this tool
Convert JSON data to TOML format. Useful when reviewing API responses, cleaning config before commit, or sharing readable snippets in docs and PRs.
Paste a JSON object into Input (arrays of primitives and nested objects work best). Click Convert to emit TOML. Example — Emit TOML from a nested JSON config: try `{ "title": "My App", "version": "1.0.0", "database": { "host": "localhost", "port": 5432 } }` and expect something like `title = "My App" version = "1.0.0" [database] host = "localhost" port = 5432`.
Not every JSON shape maps cleanly to idiomatic TOML (e.g. heterogeneous arrays). See also: TOML to JSON, JSON to YAML, and JSON Formatter. Runs in your browser — nothing you paste gets uploaded.
How to use
- Paste a JSON object into Input (arrays of primitives and nested objects work best).
- Click Convert to emit TOML.
- Copy into `*.toml` configs (Cargo, pyproject fragments, app settings).
- Prefer objects over deeply nested arrays of objects — TOML expresses tables more cleanly.
Example
Emit TOML from a nested JSON config
Input
{
"title": "My App",
"version": "1.0.0",
"database": {
"host": "localhost",
"port": 5432
}
}Output
title = "My App" version = "1.0.0" [database] host = "localhost" port = 5432
Limitations
- Not every JSON shape maps cleanly to idiomatic TOML (e.g. heterogeneous arrays).
- JSON `null` has no direct TOML equivalent and may fail or be omitted depending on the value.
- Key order in the output follows the serializer, not necessarily your original JSON order.
Related guides
1Related tools
3Frequently asked questions
What does the JSON to TOML do?
Convert JSON data to TOML format. Runs in your browser — no install, no account.
How do I use the JSON to TOML?
Paste a JSON object into Input (arrays of primitives and nested objects work best). Click Convert to emit TOML. Copy into `*.toml` configs (Cargo, pyproject fragments, app settings). Prefer objects over deeply nested arrays of objects — TOML expresses tables more cleanly.
Is the JSON to TOML free?
Yes. No signup, no usage limits, no paywall.
Does the JSON to TOML upload my data?
No. Processing happens locally in JavaScript. Your input is not uploaded, stored, or logged.
What are the limitations of the JSON to TOML?
Not every JSON shape maps cleanly to idiomatic TOML (e.g. heterogeneous arrays). JSON `null` has no direct TOML equivalent and may fail or be omitted depending on the value. Key order in the output follows the serializer, not necessarily your original JSON order.