Does this verify the signature?

No. Signature verification requires the signing key. This tool only decodes the header and payload, which is all you need to inspect claims like iss, sub, exp, and any custom data.

Is the JWT sent anywhere?

No. Decoding happens entirely in your browser — we just base64-decode two segments.

JWT Decoder

Decode a JSON Web Token to inspect header, payload, and claims.

Decode a JWT

Privacy: runs entirely in your browser. We do not verify the signature (that needs the secret key).

Token