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JWT Inspector

Decode a JWT and check exp, nbf and algorithm claims.

What Is a JWT Inspector?

The JWT Inspector decodes a JSON Web Token and also analyzes the claims for common issues. It reports the algorithm, type, key id, whether a signature is present, and checks the exp (expiration) and nbf (not before) timestamps, listing any problems it finds.

How to Use This JWT Inspector

  1. 1
    Paste your tokenEnter a JWT in the input field.
  2. 2
    Review the analysisCheck the algorithm and whether the token is currently valid.
  3. 3
    Inspect claimsRead the exp, iat, and nbf values and any listed issues.

Frequently Asked Questions

It means the token was not signed. Accepting unauthenticated tokens is a serious security issue, which this tool flags.
An expiration claim limits how long a stolen token remains usable. Without it, a token could be valid indefinitely.
No. It inspects structure and timestamps only. Signature validation requires the issuer's key, which the tool cannot know.

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