The JWT Decoder is an essential tool for developers working with authentication and authorization systems. JSON Web Tokens (JWTs) are a standard way to securely transmit information between parties as a JSON object. This tool allows you to paste an encoded JWT and instantly see its decoded components: the Header (which contains metadata like the algorithm used) and the Payload (which contains the claims or data). This is extremely useful for debugging and verifying the contents of a token during development.

1. Paste an encoded JWT string into the "Encoded JWT" textarea. You can also use the "Paste from Clipboard" button.
2. The tool will automatically decode the token as you type or paste.
3. The decoded "Header" and "Payload" will be displayed in their respective sections as formatted JSON.
4. If the JWT is malformed or invalid, an error message will be displayed.
5. You can click the copy icon on the Header or Payload cards to copy the decoded JSON to your clipboard.