Decode JSON Web Tokens (JWT) to inspect their header, payload, and signature. View claims, expiration dates, and issuer information. No validation — for inspection only.
A JWT decoder parses JSON Web Tokens to reveal their header, payload, and signature components in a readable format. JWTs are widely used for authentication and authorization in web applications, and inspecting their contents is essential for debugging login flows and API integrations. Our browser-based decoder uses native Base64 decoding to extract and display all claims including issuer, expiration, and custom data. Since the decoding happens entirely in your browser, your sensitive authentication tokens are never transmitted to any server.
A JSON Web Token (JWT) is a compact, URL-safe token format used for securely transmitting information between parties. It consists of three Base64-encoded parts: header, payload, and signature.
No. This tool only decodes the token for inspection. Signature verification requires the secret key or public key, which should never be shared in a browser tool.
Yes. The token is decoded entirely in your browser and is never transmitted to any server. However, never share JWTs containing sensitive data in untrusted environments.
'iss' (issuer), 'sub' (subject), 'aud' (audience), 'exp' (expiration time), 'nbf' (not before), 'iat' (issued at), and 'jti' (JWT ID) are standard registered claims.