Question 1

What is a JWT?

Accepted Answer

A JSON Web Token (JWT) is a compact, URL-safe token format used for authentication and information exchange. It consists of three parts: header, payload, and signature, separated by dots.

Question 2

Does this tool verify JWT signatures?

Accepted Answer

No. This tool decodes and displays the JWT contents but does not verify the cryptographic signature. Signature verification requires the secret key or public key.

Question 3

Can I see if my JWT is expired?

Accepted Answer

Yes. If the payload contains an 'exp' (expiration) claim, the tool shows whether the token is expired and displays the exact expiration date and time.

Question 4

Is my JWT data safe?

Accepted Answer

Yes. All decoding happens in your browser. Your JWT is never sent to any server. Be careful sharing JWTs as they may contain sensitive information.

Question 5

What JWT algorithms are supported?

Accepted Answer

The decoder works with any JWT regardless of the signing algorithm (HS256, RS256, ES256, etc.) since it only decodes the base64url-encoded parts without verifying the signature.

JWT Decoder

JWT Decoder