TOML to JSON converter
To convert TOML to JSON, drop your TOML file in the box below. It converts straight away; press Download to save the JSON. It all happens in your browser, so your file stays on your device.
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Converted on this device, never uploaded
What changes
| TOML to JSON | What happens |
|---|---|
| Read by | Our own TOML 1.0 reader, checked against Python’s tomllib |
| Errors | A file that breaks TOML’s rules is refused with the line and the reason |
| Tables | Become objects; arrays of tables become lists of objects |
| Dates and times | Written as ISO 8601 text, as written in the file |
| Big integers | Exact, all 64 bits |
| inf and nan | Written as the text "inf" and "nan": JSON has no such numbers |
How to convert TOML to JSON
- Add your TOML. Drop the file in the box, or click to choose it. It becomes JSON straight away.
- Check the result. Look at the preview and the size. The defaults are right for most files.
- Download. Press Download to save the JSON.
Why JSON
Read a Cargo.toml, pyproject.toml or any TOML settings file from code that speaks JSON, or check what it really sets.
Questions
Yes. Keys come out in the order the file has them.
It breaks a TOML rule, such as a key set twice or a table defined twice. The message names the line.
No. It is read and converted in your browser and never uploaded.
No. The conversion happens right in your browser, so your file stays on your device. There is no account to make, either.