JWT Decoder

How to Use JWT Decoder

Paste your JWT token string into the textarea — the standard three-part token made up of a header, payload, and signature separated by periods. The tool automatically splits the token into its components and decodes the header and payload sections, which are Base64Url-encoded JSON, displaying both as clearly formatted, syntax-highlighted JSON so you can read every claim without manually decoding anything yourself. The signature portion is displayed in hex format for reference, though note that this tool decodes and inspects the token rather than cryptographically verifying the signature, since that would require the corresponding secret or public key. Right below the decoded payload, the tool checks the token's expiry claims and shows a clear status indicator — Valid, Expired, or Invalid — based on the current time compared to the token's issued-at and expiration timestamps. The exact issued and expiry timestamps are also displayed in a readable date format, so you can see precisely when the token was created and when it stops being valid, which is invaluable when debugging authentication issues. Because JWTs often contain sensitive claims like user IDs, roles, or session data, all decoding happens entirely in your browser using standard Base64 decoding and JSON.parse — the token you paste is never sent to any server.