Convert TOML to JSON online, free. TOML is a readable configuration format built around key/value pairs and tables. JSON is the dominant data-interchange format for web APIs and config. TOML to JSON conversion parses your TOML against the TOML v1.0.0 grammar (https://toml.io/en/v1.0.0), builds an in-memory model of its keys, nested objects and arrays, then re-serializes it as valid JSON following the ECMA-404 / RFC 8259 conventions. Processing runs in your browser in JavaScript with no upload or server round-trip — no size limit beyond your device's memory, so multi-megabyte documents convert in milliseconds and sensitive payloads never leave your machine. Typical uses include REST/GraphQL API payloads, app & build configuration and logging and analytics events.
It maps the full structure of your TOML onto well-formed JSON, following the ECMA-404 / RFC 8259 conventions. 100% free, no registration, and complete privacy — everything runs locally in your browser, so your data never touches a server.
Paste TOML and convert JSON immediately. Conversion runs client-side, so there is no upload wait and large documents stay fast.
Nested TOML objects, tables and arrays are mapped faithfully onto JSON.
Your TOML never leaves your device — everything is processed locally in JavaScript, with nothing logged or stored.
Unlimited conversions with no account, no quotas, and no watermark. Works on desktop and mobile.
A TOML document and its JSON equivalent:
TOML input:
name = "Alice"
age = 30
email = "[email protected]"Output:
{
"name": "Alice",
"age": 30,
"email": "[email protected]"
}Paste your TOML into the editor and press "Convert to JSON". The tool parses it against the TOML v1.0.0 grammar, then re-serializes it as JSON following ECMA-404 / RFC 8259 conventions — instantly and entirely in your browser. You can validate or format the TOML first to be sure it is clean.
TOML values are typed and it has first-class dates and times, so they carry into JSON cleanly. TOML tables become nested JSON structures, and arrays-of-tables become lists.
Numbers, booleans and null are preserved as native JSON types wherever JSON supports them, so standard documents convert losslessly and can be read back into the same structure.
TOML (Tom's Obvious Minimal Language) (TOML) — TOML is a readable configuration format built around key/value pairs and tables. JSON (JavaScript Object Notation) (JSON) — JSON is the dominant data-interchange format for web APIs and config. This converter maps the structure of your TOML onto JSON so you can use it for REST/GraphQL API payloads.
Yes. Invalid TOML is flagged with a clear error before anything is converted. Common TOML problems to check are correct key/value pairs, quoted strings, and valid [table] headers. Starting from clean input keeps the generated JSON accurate.
Yes. The entire TOML-to-JSON conversion runs locally in your browser in JavaScript — your TOML is never uploaded, logged or stored. That matters when the data is something like Rust Cargo & Python pyproject config, which should not leave your machine.
The generated JSON is ready for REST/GraphQL API payloads, app & build configuration and logging and analytics events. Copy or download it and drop it straight into your tooling.
TOML to JSON conversion transforms Tom’s Obvious Minimal Language (a human-friendly configuration format) into JSON objects that JavaScript and APIs can process natively. TOML is designed to be simple and readable for configuration files, while JSON is the universal data interchange standard. This tool parses your TOML following the TOML v1.0.0 spec — preserving tables, nested keys, typed values, arrays, and dates — then emits valid, indented JSON entirely in your browser.
[table] and [table.subtable] syntax becomes nested JSON objects with proper nesting depth.{ inline = "table" } syntax map to JSON arrays and objects respectively.parent.child.grandchild creates proper object nesting in JSON.Convert Rust Cargo.toml metadata for web processing, transform application configuration files into JSON for deployment, parse .toml settings files from Python projects, or convert documentation frontmatter into JSON for templating — all without uploading your data anywhere.
Yes. [[array.of.tables]] syntax is fully supported and maps to JSON arrays of objects with proper nesting.
Yes. TOML dates, times, and datetime values are converted to their ISO 8601 string representation in JSON, which is the standard for date serialization.
No. Conversion runs entirely in your browser — your data never leaves your device.
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