Jwt Decoder
JSON Web Tokens (JWT) are ubiquitous in modern web authentication, securely carrying unencrypted data between client and server. The online JWT Decoder allows you to seamlessly decode any JWT string to inspect its underlying header, payload data, and algorithm structure, all from within your browser. This makes debugging stateless authentication workflows easier, ensuring that your user roles, session claims, and expiration bounds are properly structured before deployment without sending your tokens to a backend server.
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Frequently Asked Questions
Is it safe to decode my JWT here?
Yes. Our JWT decoder runs completely client-side in your browser. None of your tokens or sensitive keys are ever transmitted over the internet.
Can I verify the signature of my JWT?
Currently, this lightweight tool decodes the Base64 header and payload for inspection. Signature verification requires your secret key, which should not be pasted into web tools.
Why does my JWT look like three random strings?
A JWT is composed of three Base64-URL encoded strings separated by dots: the Header, the Payload, and the Signature.
What is an 'exp' claim in a JWT?
The 'exp' (expiration time) claim identifies the expiration time on or after which the JWT MUST NOT be accepted for processing.