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JWT Debugger

Paste any JWT token to instantly decode and view the header, payload, and signature. Supports HS256, RS256, and other common algorithms.

100% client-side · no data leaves your browser

How to decode a JWT token

Inspect a JSON Web Token's header, payload, and signature without revealing the secret.

  1. 1

    Paste the JWT

    Paste the full JWT string (three Base64URL-encoded parts separated by dots).

  2. 2

    View the parts

    The decoded header and payload appear as formatted JSON; the signature is shown raw.

  3. 3

    Check the algorithm

    Confirm the alg field in the header matches what your service expects (HS256, RS256, etc.).