Free TOML to JSON Converter Online

TOML powers config files everywhere — from Hugo and Python projects to Rust’s Cargo. Need that config as JSON for an API or a JavaScript app? Paste it below: this tool parses sections, nested sections, strings, numbers, booleans, arrays and inline tables right in your browser and hands you clean JSON, with precise line numbers when something is off.

How it works

1. Paste your TOML — config files, hugo.toml snippets, Cargo-style tables, anything.
2. Hit Convert to JSON — the built-in parser walks every line locally and reports the exact line number of any syntax problem.
3. Copy the JSON — pretty-printed with 2-space indentation, ready for your API, app, or JavaScript code.

Everyday uses

• Developers — turn TOML configs into JSON for tools that only accept JSON.
• Hugo users — convert hugo.toml settings into JSON front matter or data files.
• Python developers — inspect pyproject.toml contents in a JSON-friendly shape.
• Students — learn TOML syntax with instant, line-precise error feedback.
• DevOps — translate config files between formats during migrations.

Frequently asked questions

What TOML features are supported? Sections ([a], [a.b]), dotted keys, double-quoted strings with escapes, literal single-quoted strings, integers (decimal, hex, octal, binary), floats, booleans, arrays of scalars, and inline tables — including multi-line arrays.

What isn’t supported? Multi-line basic strings, datetimes, and [[array of tables]] — the parser tells you clearly if it meets them instead of guessing wrong.

Does inf or nan convert? No — they have no JSON equivalent, so the parser raises a clear error rather than silently writing null.

Is my TOML uploaded anywhere? No. Parsing happens entirely in your browser with an inline parser — nothing leaves your device.