JWT Decoder
Decode and inspect the header and payload of a JSON Web Token, entirely in your browser.
Header
Payload
About the JWT Decoder
A JSON Web Token (JWT) has three Base64URL-encoded parts: a header, a payload of claims, and a signature. This decoder reveals the header and payload so you can debug authentication issues.
Decoding happens entirely in your browser, your token is never sent to our servers. Note that decoding does not verify the signature; never trust a token without validating it server-side.
Frequently asked questions
No. Decoding is 100% client-side JavaScript, the token never leaves your browser.
No. Signature verification requires the secret or public key and must be done server-side. This tool only decodes the readable parts.
“iat” is issued-at and “exp” is expiry, both Unix timestamps. We convert them to readable dates for you.