Fast, private developer tools that run in your browser

Free developer tools that work instantly in your browser. Format JSON, decode tokens, convert timestamps and more. No sign-up, no uploads, no waiting.

Developer tools

JSON FormatterIndent and inspect JSON as you paste it, with errors that say what is actually wrong.JSON ValidatorCheck whether JSON is valid, see what shape it has, and find duplicate keys a parser would hide.JSON MinifierStrip whitespace from JSON and see exactly how many bytes it saved, before and after.JSON StringifyEscape a JSON document into a string literal you can paste straight into code.

How these tools work

Every tool here is a single page that does one job. You open it, paste what you have, and get an answer. There is no account, no upload step, and no processing queue.

The work happens in your browser using the same JavaScript engine that renders this page. That is not a privacy slogan, it is how the pages are built: there is no server endpoint for your input to travel to. You can confirm it by opening your browser network panel and watching nothing leave while you type.

The practical consequence is that these tools are usable for things you should not paste into a random website: production payloads, tokens from a staging environment, a customer record you are debugging. The data stays on your machine because there is nowhere else for it to go.