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JWT Debugger

Inspect JWT headers and payloads locally without leaking tokens.

JSON Formatter
JWT Debugger
Decode JWT headers and payloads locally to inspect claims without sending tokens to a server.
Ctrl+Enter Decode No signature upload Claims summary
JWT token Paste full token
0 segments | 0 chars
Decoded output Read only JSON
0 lines | 0 keys
Ready Header and payload only
Paste a JWT to inspect its decoded claims locally. Signature verification is not performed on this page.
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JWT Debugger

JWTs show up constantly in modern applications, but they are awkward to inspect by eye because the header and payload are Base64URL encoded. A local debugger makes it easy to review claims, expiry, issuer, and subject without pasting sensitive tokens into a third-party service.

This debugger decodes the header and payload segments directly in the browser and presents them as formatted JSON. It is meant for inspection, not signature verification, which keeps the interface focused and fast.

How to Use the JWT Debugger

  1. Paste a JWT into the token editor.
  2. Use Decode token to inspect the header and payload as JSON.
  3. Review claim summaries such as algorithm, subject, and expiry.
  4. Copy or download the decoded JSON if you need to share the safe, human-readable structure.

JWT Debugger Examples

Before 
eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJzdWIiOiJ1c2VyLTEyMyIsInJvbGUiOiJhZG1pbiJ9.signature
After 
{
  "header": {
    "alg": "HS256",
    "typ": "JWT"
  },
  "payload": {
    "sub": "user-123",
    "role": "admin"
  }
}

Frequently Asked Questions

  • Does this verify the JWT signature?

    No. This page decodes the token for inspection only and does not validate the signature.

  • Is token data uploaded anywhere?

    No. The token is decoded locally in your browser.

  • Can I inspect expiry claims?

    Yes. When exp or iat are present, the tool converts them into ISO timestamps for easier review.

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