Runs entirely in your browser - no upload, no sign-up.
TOML has no null value. Null array items always stop conversion so array positions never shift.
This JSON to TOML converter turns a JSON object into a readable configuration file. Nested objects become tables, arrays of objects become arrays of tables, and string values stay strings. Paste your JSON to convert it locally, resolve any unsupported values, then copy the TOML or download the file.
Enter strict JSON in the input editor, or load the example. The top-level value must be an object. Output updates as you type.
Errors identify the JSON path. Replace null values, or open Conversion options to omit null-valued object properties. Null array items must be handled explicitly.
Copy the completed output or download config.toml. Your input and converted data stay in the browser.
A nested object such as {"server": {"port": 8080}} becomes a [server] table containing port = 8080. Arrays of objects use repeated [[name]] sections. Keys containing dots, spaces or punctuation are quoted so they stay single keys.
The converter changes the file format, not the configuration schema. A JSON package description still needs the fields expected by Cargo, Hugo or your application's TOML loader. An empty JSON object produces a blank TOML document, which is valid.
Yes. It is free and needs no account. The JSON input and TOML output are processed locally in your browser. They are not uploaded or saved by the converter. Copy or download your result before closing the page.
No. TOML requires a table at the root and has no null type. This converter rejects top-level arrays and scalar values, duplicate keys, unpaired Unicode surrogates and unsupported numbers. An error clears the output so you cannot accidentally copy a partial conversion.
Conversion stops by default and shows the offending JSON path. You can explicitly choose to omit object properties with null values in Conversion options. A warning reports how many were removed. Null array items always produce an error because removing one would change array positions.
Integer tokens from -9223372036854775808 through 9223372036854775807 retain their exact digits. Decimal and exponent tokens use IEEE 754 binary64 precision and may round, as in most JavaScript applications. Overflow and underflow to zero are rejected; negative zero is normalized to zero. Put exact decimal amounts or larger integers in quotes to preserve them as strings.
No. JSON has no date type, so a date-looking string remains a quoted TOML string. This also protects version numbers and values such as "true" from changing type. Convert a string into a native TOML date manually only if your application requires it.
It generates TOML syntax from your JSON structure. It does not rename fields, infer dependencies or validate a Cargo or Python project schema. Check the required tables and settings for the application that will read the file.
Use strict JSON with a top-level object. Comments and trailing commas are not accepted. To keep the editor responsive, each input is limited to 1,000,000 characters and 64 nested objects or arrays. Split a larger configuration into smaller objects before converting.
