Dev Utility

JWT Decoder

Decode JWT header and payload segments locally to inspect claims and token metadata quickly without sending the token to a backend.

JWT token

This tool decodes the header and payload locally in the browser. It does not validate the signature.

Header

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

Payload

{
  "sub": "1234567890",
  "name": "Jane Doe",
  "iat": 1516239022
}

Frequently asked questions

Does this verify the JWT signature?

No. It decodes the Base64URL header and payload only. Signature verification requires the correct secret or public key and depends on the signing algorithm.

Is decoding the same as trusting the token?

No. Any JWT can be decoded whether or not it is valid. Always verify the signature and token claims in your actual application.

Does the token leave my browser?

This decoder works locally in the page and does not need a server round trip to parse the token segments.

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