Format and convert JSON, YAML, TOML, XML, and TOON. Everything runs locally in your browser — your data never leaves your device.
All parsing and conversion happens locally in your browser using open-source libraries. No data is uploaded to any server, and nothing is stored.
PawFormatter is a free online tool for beautifying and converting structured data. It handles the five formats you are most likely to run into when working with configuration files and APIs — JSON, YAML, TOML, XML, and TOON — and it does everything right inside your browser. You can pretty-print a dense, minified document to make it readable, or convert data from one format into another without pasting anything sensitive into a remote service. There is no account to create, no software to install, and no cost.
Using the formatter takes just a few seconds:
Each format has a sweet spot. JSON is the universal choice for data exchange between programs because it is strict and unambiguous. YAML is friendlier for humans editing configuration by hand, thanks to comments and minimal punctuation. TOML is popular for modern tooling config where clear, table-style grouping matters. XML remains common in established enterprise and document systems. TOON is a compact, token-oriented notation. PawFormatter lets you move between them so you are never stuck rewriting data by hand.
If you are deciding between two of them, our guide on JSON vs YAML breaks down the practical differences, and our walkthrough on converting TOML to JSON covers the common pitfalls with dates, comments, and root tables.
Yes. All formatting and conversion runs locally in your browser using open-source JavaScript libraries. Your data is never uploaded to a server, never logged, and never stored. Once you close the tab, it is gone.
Once the page has loaded, yes. The parsing libraries live in your browser, so you can disconnect from the internet and keep formatting and converting.
Some formats cannot represent the same things. For example, XML has no native array type, and comments do not survive a round trip through JSON. When a conversion involves such a trade-off, PawFormatter makes a sensible, predictable choice. Always review important output before relying on it.
There are no artificial limits. The only practical constraint is your own device's memory, since everything is processed locally. Very large documents may simply take a little longer.
Have a question we did not cover? Visit our FAQ or contact us — we read every message.