TOML to JSON

Convert TOML to JSON.

About the TOML to JSON

Turns a TOML file into JSON: a [table] becomes a nested object, a [[table]] becomes an array of objects, and dotted keys nest the same way they do in TOML. Handy for reading Cargo.toml, pyproject.toml, or a tool config from a script that only parses JSON. Choose an indent, press Convert, then copy or download the result. Parsing happens in your browser.

How to use the TOML to JSON

  1. Paste your TOML into the TOML panel, or press Sample to load an example.
  2. Choose an Indent of 2 or 4 spaces for the JSON output.
  3. Press Convert.
  4. Press Copy, or Download to save converted.json.

Frequently asked questions

What happens to TOML dates and times?
JSON has no date type, so they become strings. An offset date-time such as 1979-05-27T07:32:00Z is emitted as "1979-05-27T07:32:00.000Z", and a local date stays "1979-05-27".
Why does a very large integer fail to convert?
TOML integers are 64-bit, and a JavaScript number cannot hold every 64-bit value exactly. Rather than silently rounding, the parser rejects an integer it cannot represent losslessly and tells you which line it is on.
Can it convert JSON back to TOML?
Not here — this tool runs one direction only. For a round trip between config formats, the YAML ⇄ JSON converter handles both directions.
Where do the errors point?
At the offending line and column, with the reason — an unfinished array or an unexpected character, for instance — shown under the input panel.
Is my config file uploaded?
No. Config files carry registry tokens and internal package names often enough that this matters: the parse runs in your browser and nothing is transmitted.

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