JWT Decoder
Paste a JSON Web Token to inspect its header and payload. Runs fully offline.
Private by architecture: this tool runs entirely in your browser. Nothing is uploaded anywhere.
Questions, answered.
Is my token sent anywhere?
No. Decoding happens entirely in your browser — safe even for production tokens.
Does it verify the signature?
No. This tool only decodes. Always verify signatures on your server.
How do I read the expiry?
The exp claim is shown as a human-readable date, with an expired/valid badge.