JWT Decoder
Read token header, payload and expiry.
- 100% free
- No sign-up
- Runs in your browser
See what's inside a token
JWTs are Base64url-encoded JSON, so their contents are readable by anyone. Paste one to see the algorithm, claims and whether it has expired.
Decoding happens entirely in your browser, which matters when the token grants access to something.
- 1
Paste the token
header.payload.signature
- 2
Read the claims
Header and payload as JSON.
- 3
Check expiry
exp and iat as real dates.
Frequently asked questions
Does this verify the signature?
No. Verification needs the secret or public key and should happen on your server.
Is it safe to paste production tokens?
The tool works offline, but treat live tokens like passwords and revoke any you've shared.
Is my data uploaded anywhere?
No. Everything runs in your browser with JavaScript — nothing you type or open is sent to our servers.