JWT Decoder / Encoder - Verify and Sign Tokens

What is a JWT?

JSON Web Token (JWT) is an open standard (RFC 7519) for securely transmitting information between parties as a JSON object. A JWT consists of three parts: Header, Payload, and Signature, separated by dots (xxxxx.yyyyy.zzzzz).

How This Tool Works

This tool decodes the Base64Url-encoded Header and Payload of a JWT to display the JSON contents. It also parses standard claims like expiration time (exp), issued at (iat), and others into human-readable formats. All decoding happens entirely in your browser — your tokens are never sent to any server.

Common JWT Claims

• iss (Issuer): Who issued the token
• sub (Subject): Who the token is about
• aud (Audience): Intended recipient
• exp (Expiration): When the token expires
• iat (Issued At): When the token was created
• nbf (Not Before): Token is not valid before this time