JWT TOOLKIT
JWT toolkit, decode and sign without uploads.
Paste a JWT on the left to view its Header and Payload (with expiry conversion); on the right, generate a token signed with HS256/384/512 or none using your secret.
Decode JWT
Create JWT
Everything runs locally in your browser
What does this tool do?
A JWT (JSON Web Token) is three parts — Header, Payload and Signature — joined by dots. This tool decodes any JWT to show its contents and converts time fields like exp/iat; it can also build a token from your Header, Payload and secret using an HMAC-SHA algorithm (none means unsigned, for debugging only).
FAQ
Is my secret safe?
Yes. Signing runs entirely in your browser with Web Crypto; the secret and token never leave your device and are not sent anywhere.
What is the none algorithm for?
none means the token is unsigned — only useful for local debugging or learning the JWT structure. Never use it in production, since anyone can forge such a token.