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JWT Header Viewer Examples

Review practical JWT Header Viewer examples so you can understand expected input, output, and common patterns faster.

Why examples matter for JWT Header Viewer

Use this JWT Header Viewer to decode only the first part of a JWT token and display the header as readable JSON. It is useful when you only need to inspect header values such as alg, typ, kid, cty, and other metadata without parsing the full payload.

Example pages are especially useful for developer tools because they show what good input looks like, what kind of output to expect, and how the tool behaves in common scenarios.

JWT Header Viewer examples

View a simple JWT header

Input

eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJzdWIiOiIxMjMifQ.signature

Output

{
  "alg": "HS256",
  "typ": "JWT"
}

Useful when checking only the algorithm and token type.

View a header with kid

Input

eyJhbGciOiJSUzI1NiIsImtpZCI6ImtleS0xIiwidHlwIjoiSldUIn0.eyJzdWIiOiIxMjMifQ.signature

Output

{
  "alg": "RS256",
  "kid": "key-1",
  "typ": "JWT"
}

Helpful when troubleshooting key selection and signing metadata.

How to use these examples

  1. Paste the full JWT token into the input box
  2. Click Run Tool to decode the header segment
  3. Review the JSON output for header values
  4. Copy the result for debugging or comparison
  5. Use JWT Decoder or JWT Parser if you also need the payload

Common mistakes in sample input

The token is incomplete or does not contain dot-separated parts

Fix: Paste the full JWT token with header, payload, and signature sections.

The user expects payload claims too

Fix: Use JWT Decoder or JWT Parser if you need the payload.

The header segment is not valid Base64 URL data

Fix: Check whether the token was copied fully and is actually a JWT.

Next steps

After reviewing these examples, run the live tool with your own input. If your task involves a follow-up step, the related page can help you move to the next tool in the workflow.

Run the main tool

Open the main JWT Header Viewer page and test your own real input.

Open JWT Header Viewer