JWT Decoder
Paste a JSON Web Token to instantly decode its header, payload, and claims. Check expiration status and inspect all token data client-side.
What is a JWT?
A JSON Web Token (JWT) is a compact, URL-safe token format used for securely transmitting information between parties. It consists of three Base64URL-encoded parts: a header, a payload, and a signature, separated by dots.
- Authentication and authorization in web apps.
- Stateless session management.
- API access tokens and refresh tokens.
- Single sign-on (SSO) implementations.
Security Note
This tool decodes JWTs entirely in your browser. No data is sent to any server. Remember that decoding a JWT does not verify its signature — anyone can read a JWT payload. Signature verification requires the secret key or public key and should always be done server-side.