Free TOML to JSON Converter

The TOML to JSON Converter is a free online tool that convert toml configuration files to json format instantly in your browser. It runs entirely in your browser with no installation or sign-up needed.

Yes — the converter handles all standard TOML types including strings, integers, floats, booleans, arrays, and tables.

Yes, completely free with no registration required. All conversion happens in your browser.

Absolutely. The TOML to JSON Converter processes everything client-side in your browser. No data is uploaded to or stored on any server. Your content remains private on your device at all times.

Yes, the TOML to JSON Converter is fully responsive and works on smartphones and tablets. You can use it on any device with a modern web browser -- no app download required.

No account or registration is needed. Simply open the TOML to JSON Converter in your browser and start using it immediately. There are no sign-up walls or usage restrictions.

Simply enter your input in the provided field, adjust any settings to your preference, and the tool will process it instantly. You can then copy the result to your clipboard or download it.

The TOML to JSON Converter works in all modern browsers including Chrome, Firefox, Safari, Edge, and Opera. For the best experience, use the latest version of your preferred browser.

TOML (Tom's Obvious, Minimal Language) and JSON describe the same kind of nested key/value data, but they target different readers. TOML is written for humans: it uses comments, unquoted keys, multi-line strings, dates, and section headers like [server] that read almost like an INI file, which is why tools such as Cargo and pip use it for configuration. JSON is written for machines: stricter syntax, no comments, every key quoted, and parsers built into nearly every language. The structures map cleanly onto each other — a TOML table becomes a JSON object, an array of tables becomes an array of objects — so converting between them is lossless for standard data. When you need TOML config in a JSON-only script, viewer, or API, paste it above and get the equivalent JSON instantly.

A standard table header like [server] becomes a nested JSON object under the "server" key, and a dotted header such as [server.database] nests another object inside it. Dotted keys like package.name = "x" expand the same way into the matching object structure. An array of tables — written with double brackets, for example [[bin]] repeated several times — is collected into a JSON array of objects, so three [[bin]] blocks produce a "bin" array with three entries. Inline tables written as { version = "1.0", features = ["derive"] } are parsed in place into an object, exactly how Cargo dependency lines are structured. The converter applies these rules deterministically, preserving the original shape of your file. Paste a real manifest and watch the nested objects and arrays build up live in the output panel.

The parser covers the full range of TOML scalar types, not just plain strings and integers. Integers can be written in decimal, hexadecimal (0x), octal (0o), or binary (0b), and underscore digit separators like 1_000_000 are accepted and stripped — each is converted to the equivalent numeric value in JSON. Floats include the special forms inf, +inf, -inf, and nan. Booleans become true or false, and ISO 8601 dates and local times are recognized as date values. Basic, literal, and multi-line strings (triple-quoted with """ or ''') are all supported, and full-line plus inline # comments are stripped, including a comment trailing a value or array. Because JSON has no native date or infinity type, those are emitted as their closest JSON representation. Paste your config to see every type converted correctly.

If the converter reports an error instead of JSON, the source TOML has a syntax problem the parser cannot resolve, and the message names the exact line — for example "Line 12: Duplicate key" or "Unterminated array." Common causes are defining the same key twice in one table, opening a bracket or quote that is never closed, an inline table missing its closing brace, or a [table] header that is not terminated. Go to the reported line in your source file rather than guessing: close the open string, remove the duplicate assignment, or finish the array. TOML is intentionally strict, so a single stray character on one line is enough to stop parsing. Fix that line, paste again, and the JSON appears immediately — the line number points you straight to the problem.

They control only how the JSON is formatted, never its data. Choosing 2-space or 4-space indentation pretty-prints the output with that many spaces per nesting level, which makes deeply nested tables easy to read and to diff in a JSON-aware viewer. Switching to Minified strips every space and newline, collapsing the result onto a single line for the smallest possible payload — useful when the JSON is going into a request body, an environment variable, or anywhere size matters. The keys, values, and structure are identical across all three; only the whitespace differs, so a minified file parses to exactly the same object as the indented version. A live stats row also shows input lines, output byte size, and total key count. Pick the format you need, then copy or download the result.