JWT Decoder

JWT (JSON Web Token) is a compact, URL-safe means of representing claims to be transferred between two parties. JWTs are commonly used for authentication and authorization in web applications and APIs.

A JWT consists of three parts separated by dots: Header, Payload, and Signature. The header typically contains the token type and signing algorithm. The payload contains the claims (statements about the user and additional metadata). The signature is used to verify the token hasn't been tampered with.

This decoder extracts and displays all three parts of a JWT token in human-readable format. It automatically identifies standard claims like expiration time (exp), issued at (iat), issuer (iss), and subject (sub), and highlights expired tokens. Note: This tool only decodes and displays JWT contents - it does not verify the signature or validate the token's authenticity.