How to use
- Paste the source, open a UTF-8 file or try the Sample.
- Choose the options and run the conversion or enable Auto run.
- Review the result, then copy a selection or download the complete text.
JSON to TOML Converter
Paste a JSON object. Nested objects become TOML tables and object arrays can become arrays of tables. The serializer emits TOML locally; the result is available as text or a .toml download.
Processing stays in your browser. DevToolsy does not receive the pasted data or selected file.
Input and processing
Strings remain strings even when they look like dates. Integer tokens must fit the signed 64-bit range. Decimal values are checked for round-trip compatibility before passing through the serializer.
{"title":"DevToolsy","server":{"host":"127.0.0.1","ports":[3000,8080]}}title = "DevToolsy"
[server]
host = "127.0.0.1"
ports = [ 3000, 8080 ]
This example uses the default settings.
Result and limitations
TOML has no null, so null is rejected rather than dropped. Unsupported decimal precision also produces an error. JSON has no comments or native date types for the converter to reconstruct.
Using the output
Review the result, then copy a selection or download the complete text.
UTF-8 input up to 1 MiB; output up to 8 MiB. Processing stops after 30 seconds.
Frequently asked questions
How are JSON objects converted to TOML tables?
Paste a JSON object. Nested objects become TOML tables and object arrays can become arrays of tables. The serializer emits TOML locally; the result is available as text or a .toml download.
How are strings and numeric values handled?
Strings remain strings even when they look like dates. Integer tokens must fit the signed 64-bit range. Decimal values are checked for round-trip compatibility before passing through the serializer.
What happens to null or unsupported numbers?
TOML has no null, so null is rejected rather than dropped. Unsupported decimal precision also produces an error. JSON has no comments or native date types for the converter to reconstruct.
Is the input uploaded?
Processing stays in your browser. DevToolsy does not receive the pasted data or selected file.
Can I keep the result?
Review the result, then copy a selection or download the complete text.