JSON to TOML
Runs locally in your browser. Nothing leaves your device.Convert strict JSON to readable TOML locally in the browser.
Input
Check null values, large numbers, and date strings. Date strings remain strings by default.
Output
Paste valid JSON to generate TOML.
Paste valid JSON to generate TOML.
How it works
- 1
Paste the JSON
Paste valid JSON into the input field.
- 2
Set the null strategy and root mapping
Choose the null strategy, root mapping, and optionally a JSON Pointer.
- 3
Copy or download the TOML
Copy the generated TOML or download it as a file.
Good to know
The JSON to TOML converter converts JSON into TOML directly in your browser. Since TOML has no null value, a null strategy determines whether null values trigger an error, are omitted as an object property, or are output as the text "null". Since TOML also requires a root table, root arrays or root scalars are explicitly wrapped with a configurable wrapper key when needed.
A JSON Pointer such as /data/config deliberately selects a subtree from the source. Important: date strings stay strings by default instead of becoming TOML date values; also check null values and large numbers, since JSON and TOML don't share the same data types.
Typical use cases
Migrate a project configuration from JSON to TOML
Convert an existing JSON configuration to TOML, for example for Rust Cargo or Python project files that expect TOML.
Export only part of a large JSON configuration
Use a JSON Pointer like /data/config to deliberately export only the relevant subtree as TOML.
Tips for better results
Choose the null strategy to match the target parser
If the target parser expects optional fields, “omit” is often more suitable than an error or a text null.
Check date strings after conversion
Since date strings stay strings by default, check whether the target parser expects native TOML date values instead.
Features
Configurable null strategy
Error, omit, or text "null" for JSON null values without a TOML equivalent.
Root wrapper for arrays and scalars
Root arrays or scalars are wrapped with a configurable key into a valid root table.
Local processing
Your data never leaves your device; conversion runs entirely in the browser.
Frequently asked questions
What happens to JSON null in TOML?
Since TOML has no null value, you can choose: trigger an error, omit the property, or output as the text "null".
Is my data uploaded?
No. Conversion runs entirely locally in the browser.
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