A JSON Web Token (JWT) is a compact, URL-safe format used to represent claims between two parties. JWTs are widely used for authentication, session management, and information exchange in modern web applications. Each token consists of three Base64URL-encoded parts separated by dots: header, payload, and signature.
This JWT decoder splits the token and decodes the header and payload sections,
displaying the JSON contents with proper formatting. It color-codes the three sections so you
can easily identify which part is which. If the payload contains an exp (expiration)
claim, the tool shows whether the token has expired.
Note: this tool only decodes the token. It does not verify the signature, which would require the signing secret or public key. For security-sensitive verification, use your backend JWT library. All decoding happens locally in your browser and no token data is transmitted.