JWT Decoder: Inspect JSON Web Token Contents
Decode JSON Web Tokens to inspect their header, payload, and expiration without any secret key. Essential for debugging authentication flows.
What It Does
The JWT Decoder splits a JSON Web Token into its three parts: header, payload, and signature. It displays the decoded header algorithm and type, the full payload with all claims, and checks whether the token has expired based on the exp claim.
How to Use It
Paste a JWT string into the input field. The tool instantly decodes and displays the header and payload in a readable JSON format. Expiration status is shown prominently. Copy individual sections or the formatted output.
Tips & Tricks
Check the exp claim to see when a token expires. The alg field in the header tells you which signing algorithm was used. Remember that decoding is not the same as verifying, always verify signatures server-side.
Use Cases
Backend developers debug authentication issues by inspecting token contents and expiration. Security auditors review JWT configurations for proper algorithm usage. Front-end developers check token payloads to understand available user claims.
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