Decode JSON Web Tokens instantly with this free JWT decoder online. Paste your JWT token to see the decoded header, payload, and expiration status -- all processed locally in your browser with nothing sent to any server.
A JWT (JSON Web Token) is a compact, URL-safe token format defined by RFC 7519. It consists of three Base64url-encoded parts separated by dots: a header (algorithm and type), a payload (claims about a user or session), and a signature. JWTs are commonly used for authentication, authorization, and secure information exchange between services. This JWT decoder lets you inspect the header and payload without needing a secret key.
This tool decodes and displays the header and payload, but it does not verify the cryptographic signature. Signature verification requires the secret key (HMAC) or public key (RSA/ECDSA), which should never be shared with a web tool. This decoder is designed for inspecting token contents, checking expiration times, and debugging claims -- tasks that do not require the signing key.
When a JWT payload contains an "exp" (expiration time) claim, this decoder compares that Unix timestamp to your current system time. If the expiration time is in the past, the token is marked as expired. If it is in the future, you will see a "valid" status with the remaining time. Tokens without an "exp" claim are flagged accordingly since they never expire on their own.
Yes. This JWT decoder runs entirely in your browser using JavaScript. Your token is never transmitted to any server, stored, or logged. You can confirm this by monitoring the Network tab in your browser's developer tools. However, as a general security practice, avoid sharing production tokens with any third-party service. If a token has been compromised, revoke it through your authentication provider.