Jwt Decoder

A JWT decoder can display a token's header and payload by base64url-decoding them. This is useful for debugging claims such as issuer, audience, subject, and expiration, but anyone can decode—or alter—a payload. Reading it is not the same as verifying the signature or trusting the claims.

Use a synthetic token when exploring a web tool; a real bearer token can grant access if exposed. For application decisions, verify the signature with an allowed algorithm and trusted key, then check issuer, audience, time claims, and intended use. RFC 8725 warns against trusting token-supplied algorithm choices or received claims blindly.