Header
Decoded JSON
Algorithm and token metadata from the first JWT segment.
{
"message": "Decoded header will appear here"
}
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JWT Decoder
Decode JSON Web Tokens Instantly
Paste a token to inspect its header, payload, signature, and common time-based claims. Decoding happens instantly in your browser.
Overview
Token Details
Expiry State
Unknown
Issued At
Not available
Expires At
Not available
Notes
Waiting for token
Payload
Decoded JSON
Claims from the second JWT segment, pretty-formatted for review.
{
"message": "Decoded payload will appear here"
}What Is A JWT?
A compact token format for claims
A JSON Web Token is a compact string made of three dot-separated parts: header, payload, and signature. The header describes the token type and algorithm, the payload contains claims, and the signature helps detect tampering.
JWT Encoding And Decoding
What this decoder is showing you
This tool base64url-decodes the header and payload so you can read the JSON they contain. It does not prove the token is trustworthy by itself; trust depends on validating the signature with the correct secret or public key in your own auth system.
JWT Best Practices
Keep payloads boring and short-lived
Avoid placing secrets or sensitive personal data in a JWT payload, because anyone holding the token can decode it. Prefer short expiration windows, use HTTPS everywhere, and protect your signing keys carefully.