JWT Decoder - Free Online | FunToolX
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JWT Decoder
Paste a JWT token to decode its header and payload locally — inspect expiry and claims. Nothing leaves your browser.
About this tool
JWT Decoder is a free online tool. Decode the header and payload of a JWT token locally — inspect expiry and claims without sending data anywhere.
By pasting the JWT string (Base64 encoding starting with eyJ), the tool will automatically split the three parts (header.payload.signature), decode and display the JSON content. The header contains the algorithm and type, and the payload contains user information and declarations (such as sub, iat, exp). The expiration time will be highlighted and whether the flag has expired will be marked.
The header and payload of JWT are encoded using Base64URL, and the tool decodes it and formats JSON for display. The signature part cannot be decoded (requires a key), but you can verify that the signature is valid (if the key is provided). The tool also resolves timestamp declarations (iat, exp, nbf) into readable dates.
Suitable for developers to debug JWT certification and view the user information contained in the token. Verify that the token is out of date, or check that the statement is correct.
JWT decoding tool that parses the header, payload and signature of JSON Web Token, and displays expiration time and declaration information.