JWT Decoder
How to Use
Paste a JWT token into the input field. The tool instantly decodes and displays the header (algorithm and type), payload (claims and data), and signature. Expiry status is automatically checked against the current time.
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 separated by dots: header (algorithm metadata), payload (claims like user ID, expiry, issuer), and signature (cryptographic verification). JWTs are widely used in OAuth 2.0, OpenID Connect, and API authentication.
Privacy & Security
All decoding happens entirely in your browser. Your token is never sent to a server, stored, or logged. Note: this tool only decodes tokens — it does not verify signatures. Never paste production tokens containing sensitive data into untrusted online tools.