JWT Decoder
Decode and inspect JWT tokens. View header, payload, and verify structure.
Encoded JWT
Paste your token here
Decoded Data
Header, Payload, and Signature
About JWT Decoder
The JWT Decoder safely unpacks JSON Web Tokens (JWT) into their readable Header and Payload components. It automatically formats the JSON objects and highlights timestamps, making it effortless to debug authentication issues.
How to Use
Real-World Examples
Decoding an Authentication Token
Unpack a JWT to inspect the user claims, expiration time (exp), and issued-at time (iat).
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Header: {
"alg": "HS256",
"typ": "JWT"
}
Payload: {
"sub": "1234567890",
"name": "John Doe",
"iat": 1516239022
}Best Practices
- Never place sensitive information (like passwords or credit card numbers) in a JWT payload, as it can be easily decoded by anyone who intercepts it.
Pro Tips
Hover over the `iat` and `exp` claims in the decoded payload to see the human-readable date and time.
Frequently Asked Questions
Does this tool validate the signature?
Yes, if you provide the secret key or public certificate, the tool will locally verify the signature to ensure the token wasn't tampered with.
Is my data secure?
Absolutely. All processing is done locally in your browser. Your data is never sent to our servers.
Security & Privacy
Tokens are decoded instantly via JavaScript using Base64 decoding. Your JWTs, which often contain sensitive session data, never leave your browser.