Developer tools that never see your data.
JsonKit is a set of 84 free developer tools that run in your browser. Paste a production payload or an access token, or drop in a QR image. None of it is uploaded, logged or stored on a server.
Most JSON tools upload your data. We didn't want to.
The quickest way to format or convert some JSON is to paste it into the first website that turns up. Many of those sites send what you paste to a server. That is a problem when the JSON is a production response, an auth token or someone's personal data.
JsonKit does the opposite. Every tool runs locally, so your input is processed on your own machine and is never sent anywhere. There is no network round trip, so it is fast. There is also nothing for us to log, leak or sell. We built it because we wanted it ourselves.
What JsonKit stands for
Your data stays in the tab
Every tool runs on your device with JavaScript. Once a tool page has loaded, it keeps working offline. There is no server to send your JSON to.
Results as you type
There is no submit button and no round trip. Output updates as you type. Errors show the line and column.
Keyboard shortcuts
Press ⌘K to jump between tools, ⌘↵ to run and ⌘C to copy the output. You can use the toolkit without the mouse.
No signup, no paywall
All 84 tools are free, with no file size limit and no ads. There are no accounts, so nothing sits behind a login.
What's inside
84 tools across four families, each on its own page and pre-filled with sample data.
Format
Prettify, minify, escape and repair JSON. Make it readable or make it small.
Validate
Check JSON against a schema, diff two payloads line by line, and decode JWTs to inspect their claims.
Convert
Convert JSON to and from CSV, YAML and XML, or generate TypeScript types from it.
Query & Generate
Pull values out with JSONPath, generate mock data and schemas, or create QR codes for text and Wi-Fi.
Found a bug or have an idea?
Tell us what's broken or what you wish JsonKit did. We read every message.