Toolzie

JWT Decoder

Decode JSON Web Tokens instantly. Nothing is sent to any server.

How to Use the JWT Decoder

Paste JWT. See header, payload, signature. Timestamps become human-readable. Copy details.

Debugging auth issues requires JWT inspection. Decode instantly without terminal.

Frequently Asked Questions

What is JWT?

Compact URL-safe token representing claims; common for auth.

Safe?

Yes, local decoding only.

Verify signature?

Shows signature; cannot verify without key.

Claims?

iss (issuer), exp, sub, aud, iat common.

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About This Tool

Decode and inspect JSON Web Tokens (JWTs) instantly with the Toolzie JWT Decoder. See the header, payload, and signature of any JWT — useful for debugging authentication flows in web applications.

How to Use

  1. Paste your JWT token into the input field.
  2. The header and payload are decoded and displayed as formatted JSON.
  3. Review claims like exp (expiry), iat (issued at), and sub (subject).
  4. Check the token expiry time against the current timestamp.

Frequently Asked Questions

Is it safe to paste my JWT here?

JWTs are decoded locally in your browser — they are not sent to any server. However, avoid pasting production tokens from sensitive systems as a general security practice.

Does this verify the JWT signature?

Signature verification requires the secret key. This tool decodes the payload without verifying the signature.

What is a JWT used for?

JWTs are used to securely transmit authentication and authorization claims between a client and server in web applications.

What does the 'exp' claim mean?

The exp claim is a Unix timestamp indicating when the token expires. This tool shows the human-readable expiry time.