Paste a JWT token on the left, or click Sample Token to try an example
JWT (JSON Web Token) is a compact, URL-safe string used for stateless authentication. It contains three parts separated by dots: header (algorithm), payload (claims), and signature. JWTs are commonly used in modern APIs and OAuth2 flows.
Paste your JWT into the left panel and this tool will decode it instantly. Check the payload for the expiration time (exp claim) — if it's in the past, the token has expired. The signature validates that the token hasn't been tampered with.
JWTs are stateless, meaning the server doesn't need to store session data. They're compact, can be transmitted in headers or URLs, and include cryptographic signatures for security. This makes them ideal for microservices and mobile apps.