JSON to TOML Converter
Paste a JSON sample to instantly convert it into a valid TOML document, with nested objects turned into table sections. Free online developer tool.
Paste JSON
TOML Document
TOML output will appear here...
Free JSON to TOML Converter
Paste a JSON sample to instantly convert it into a valid TOML document. Unlike this tool's type-generator siblings, TOML has no schema concept — the output is a real TOML document populated with the actual values from your sample, with nested objects becoming [table] sections and arrays becoming TOML arrays.
How to Use It
Paste any JSON object into the input box, or click "Load Example" to see a sample run. The converter walks your JSON and emits key = value pairs for scalars and arrays of scalars, and turns each nested object into its own [table] section (or[[table]] for arrays of objects) using dotted paths to represent nesting.
Example
Given {"name": "Ann", "tags": ["a","b"], "address": {"city": "NYC", "zip": "10001"}}, the tool emits name = "Ann" and tags = ["a", "b"]at the top level, followed by an [address] section containingcity = "NYC" and zip = "10001".
Common Use Cases
- Converting a JSON config export into a TOML config file for tools like Cargo or Poetry.
- Migrating settings from a JSON-based app to a TOML-based one.
- Producing a human-readable sample TOML document from real API response data.
- Quickly checking how a nested JSON structure would look expressed as TOML tables.
FAQs
Why does this tool output values instead of type declarations?
TOML is a configuration file format, not a schema/type language — there's no TOML equivalent of a TypeScript interface. Instead, this converter produces a real, valid TOML document populated with the sample values from your JSON, which you can use directly as a config file or as a template.
How are null values handled, since TOML has no null?
TOML has no native null/nil value, so any field that was null in your JSON is emitted as an empty string with a trailing comment noting it was null in the source, so you can decide how to represent it for your use case.
Is my JSON uploaded anywhere?
No — parsing and TOML generation happen entirely client-side in your browser. Nothing you paste is sent to a server.