A JSON Web Token (JWT) is a compact, URL-safe way to represent claims between two parties. It consists of three base64url-encoded parts: a header, a payload, and a signature.
No. All decoding happens entirely in your browser. Your token never leaves your device.
This tool only decodes and inspects the token. Signature verification requires the secret key or public key, which is not handled here.
If the token has an 'exp' claim and that timestamp is in the past, the token is expired. The expiry status is calculated using your device's current time.