Query String to JSON

Paste your Query String into the box above and the JSON appears instantly below — there is no button to press and nothing to upload. The conversion runs entirely in your browser, so it is fast and private, and you can copy the result or download it as a file. If the input has a syntax error, a clear message tells you what to fix.

Yes on both counts. It is completely free with no signup or limits, and it is private because the whole conversion happens locally in your browser — your data is never sent to any server. That makes it safe for API responses, config files and other sensitive data, which never leave your device.

JSON (JavaScript Object Notation) is the standard data format used by almost every web API and config file. Converting Query String to JSON lets you reuse the same data in tools and systems that expect JSON instead of Query String, without retyping it by hand.

No — the values are preserved exactly; only the surrounding format changes. A query string is the key=value part of a URL after the “?”, the way browsers pass parameters to a page, and the converter maps every key and value across to the equivalent JSON structure. Comments and exact spacing may not carry over, since the two formats represent them differently, but the data itself stays intact.

There is no fixed limit because nothing is uploaded — the only real constraint is your device’s memory, so even large inputs convert instantly on a normal computer. Very large files of tens of megabytes are handled more comfortably on a desktop browser than on a phone.

Yes. It runs in any modern browser on Windows, Mac, Linux, iPhone and Android with nothing to install, and because the conversion is client-side JavaScript it keeps working offline once the page has loaded. The result can be copied or downloaded on any device.