Decode any JSON Web Token to reveal its header and payload. Client-side only — your token is never sent to a server. Shows algorithm, claims, and expiry.
Open JWT Decoder → free, no sign-inJWTs (JSON Web Tokens) carry encoded claims in three Base64url-encoded sections: header, payload, and signature. Decoding a JWT to see what's inside — the algorithm, the user claims, the expiry time — usually means either writing code or hunting for a decoder. The JWT Decoder does it instantly: paste the token, see the decoded header and payload in a readable format.
Developers debugging authentication flows, security engineers auditing token contents, anyone integrating with a JWT-based auth system who needs to verify what claims a token contains.
No tutorials. No learning curve. Open it and get started.
No server uploads. Client-side only — the token is decoded in your browser, never sent to a server. Important for tokens containing sensitive user data.
Completely free. No trial period. No premium tier for basic functionality. No account required. Use it as often as you need.
One job, done well. JWT Decoder was built to solve a specific problem cleanly. No feature bloat, no ads, no distractions.
Can this be used to forge a JWT?
No — decoding only reads the claims. Forging a JWT requires the secret signing key.
Is my token safe to paste here?
The tool is client-side only — your token isn't sent anywhere. For production tokens containing PII, be mindful of browser history.
What are JWT claims?
Claims are statements about the subject — typically user ID, roles, permissions, and expiry time.
Can I verify the signature?
Signature verification requires the secret key or public key. The decoder shows the algorithm used.
Why does the expiry show a past time?
The token has expired — your server should be rejecting it.
Free. Instant. No sign-in. Open it and get the job done.
Open JWT Decoder on Doathingy.com →