Developer tools that run in your browser
Format JSON, decode a JWT, test a regex, convert a timestamp — the small jobs that interrupt a working day, done instantly and without uploading anything.
Why not just paste it into the first site that comes up?
Because the things developers reach for these tools with are rarely harmless. A JWT from a staging environment carries a real user id and real claims. An API response you want pretty-printed contains whatever that endpoint returns. A connection string ends up in a Base64 box more often than anyone admits. Every tool here runs as plain JavaScript in your own tab: nothing you paste is sent anywhere, so there is no server log to worry about and no vendor to trust.
Built for the middle of a debugging session
These are not applications. There is no account, no workspace, no project to create first. A page loads, you paste, you get the answer, you close the tab. That matters when the tool is a two-second detour inside a much longer task — decoding a token to check why an endpoint returns 401, diffing two config files to find the one line that differs, converting a Unix timestamp in a log line into something human. The tools stay fast because there is no round trip: your browser computes the result as quickly as it can, even on large inputs.
What each one is actually for
The JSON formatter validates as it pretty-prints, so a syntax error tells you where. The JWT decoder shows the header and payload without verifying — deliberately, since verification needs a secret you should not paste into a web page. The regex tester matches as you type against a sample. The hash generator produces MD5, SHA-1 and SHA-256 for checksum comparison, not for password storage. The diff checker highlights changes inline rather than dumping a unified patch. The rest — UUID, Base64, URL encoding, number bases, timestamps — are the conversions you would otherwise write a throwaway script for.
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