TOKEN INSPECTION

JWT decoder

JSON Web Tokens carry authentication claims between services and clients.

Decode JWT segments

Decode-only helper. Signature verification should stay server-side.

Header

 

Payload

 

Signature:

Why this tool works well

  • Readable JSON output for header and payload claims.
  • Clear signature segment status without pretending verification.
  • Fast local decoding for incident triage and QA.
  • When an API returns a 401 Unauthorized error, decode the token you are sending to check whether it has expired. The exp claim is a Unix timestamp — compare it to the current time to confirm.
  • During OAuth integration testing, decode the access token to verify the scopes and audience fields match what your application expects before writing validation logic.

Use cases

Auth debugging

Inspect token claims when sessions behave unexpectedly.

Environment checks

Compare payloads across staging and production tokens.

Support workflows

Read exp and aud claims during troubleshooting.

Practical examples

Header review

Input: Encoded header segment

Output: Parsed alg/kid JSON block

Payload audit

Input: Encoded payload segment

Output: Readable claims list

Suggested workflow

FAQ

Does this verify signatures?

No, this tool decodes only. Signature verification must happen in trusted backend logic.

Is token data stored?

No, decoding runs in your browser.

Does this tool verify the JWT signature?

No. This tool decodes the header and payload for inspection only. Signature verification requires the secret key or public key and should be done server-side or with a dedicated library.

Is it safe to paste a production JWT here?

Decoding runs entirely in your browser with no server calls. However, treat production tokens as sensitive credentials and rotate them if you paste them into any tool you do not fully control.

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