Dev / JWT
Decode a JWT header and payload
Base64url decode only. Signature is not verified. There is no key server.
Last checked: September 2026. Confirm millimetres, pixels, and KB on the official form. Not a government website.
Runs in this tab. 0 uploads. MD5 is a checksum, not security.
Header and payload are decoded locally. Signature is not verified — there is no key server here.
{
"header": {
"alg": "HS256",
"typ": "JWT"
},
"payload": {
"sub": "1234",
"name": "Cherry",
"iat": 1516239022
},
"signature": "signature"
}01
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02
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03
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FAQ
Questions, answered
Verify signature?Open
No. Verification would need a key. We will not send the token anywhere to check it.
Is anything uploaded?Open
No. This tool runs in your browser tab. Close it and the data is gone.
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