Developer tool
Your files never leave your device
Check your Network tab and see
Work starts the moment you drop a file
No daily limit, no sign-up, no watermark
Use this to inspect structure or mock a token in a local app that ignores signatures. Real auth needs your backend and a vaulted secret.
We use standard btoa, not JWT’s URL-safe alphabet. Some libraries will reject the token until you swap +/ and padding.
Encoding happens locally, so nothing is transmitted — but still avoid pasting live user data or real secrets you would not put into any text box.
That is the promise behind every tool here. Files are read in your browser tab, processed there, and discarded when you close it — never uploaded to our servers.
Decode JSON Web Tokens (JWT) safely to view header and payload without sending secrets to any server.
HMAC-SHA256 in the browser.
Encode to Base64 or decode from Base64 instantly in your browser.
MD5 for checksums plus SHA-1, SHA-256, and SHA-512 via Web Crypto — all in your browser, nothing uploaded.
Format, validate, prettify and beautify your JSON data instantly.
Generate valid universally unique identifiers (UUIDs/GUIDs) instantly.
