How are dates represented in JSON?

RFC 3339 datetimes are converted to ISO-8601 strings and the tool tells you how many were converted, because JSON has no date type. Going back to TOML, ISO-8601 strings can be turned into native datetimes again.

Can I convert JSON back to TOML?

Yes. Switch to JSON → TOML. The top level must be an object, arrays must hold a single type, and nulls are either dropped (default, with a note) or reported as an error.

TOML to JSON

Turn TOML (Cargo.toml, pyproject.toml, netlify.toml and more) into equivalent JSON, or convert JSON into TOML. Supports tables, arrays of tables, inline tables, dotted keys, multi-line strings and native datetimes. Errors are reported with line and column, and every lossy step, such as datetimes becoming strings or nulls being dropped, is listed.

Runs locally in your browser

For large TOML, open fullscreen for a wider view

Presets

TOML input

0 chars · 1 line

JSON output

Output will appear here…

Indent

Sort keys alphabetically

TOML 1.0: tables, arrays of tables, inline tables, dotted keys, multi-line strings and native datetimes (emitted as ISO-8601 strings, because JSON has no date type).

YAML to JSON

Convert YAML into strict JSON, with multi-document streams, YAML-only types and duplicate keys handled.

XML to JSON

Convert XML to JSON and JSON back to XML, with attribute, text-node, namespace and array controls.

JSON to YAML

Convert JSON into clean YAML with control over quoting, wrapping, anchors and multi-document output.

How to use TOML to JSON

1Choose TOML → JSON or JSON → TOML. Swap reverses the direction using the current output.
2Paste or upload, or load a preset (Cargo, pyproject, netlify) to see the shapes.
3For JSON → TOML, decide whether ISO-8601 strings become native datetimes and whether nulls are dropped.
4Copy or download the result.

About TOML to JSON

TOML to JSON is part of FizzKit — a collection of focused developer and ad-tech tools. Because everything runs locally, it works offline once loaded and never exposes your data to a remote server.

Frequently asked questions

TOML 1.0.0, per the official spec.

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