JWT Decoder
Decode a JWT's header and payload entirely in your browser — your token is never sent to a server. Known claims like exp, iat and nbf are converted to readable dates automatically.
Your data is processed locally in your browser
How to Use the JWT Decoder
- 1Paste your JWT into the input field.
- 2View the decoded header and payload.
- 3Check known claims like exp, iat and sub, converted to readable dates.
Frequently Asked Questions
Is my JWT sent to a server?+
No. Decoding happens entirely client-side in your browser — the token never leaves your device.
Does this verify the token's signature?+
No. This tool only decodes the Base64URL-encoded header and payload; it does not verify the signature. Decoding a JWT does not mean it is valid or trustworthy.
What are exp, iat and nbf?+
They're standard timestamp claims: expiration time, issued-at time and not-before time. They're shown converted to human-readable dates.