JWT Decoder
Decode a JSON Web Token to inspect its header, payload and expiry.
About this tool
A JWT packs a header, a payload of claims and a signature into three Base64URL segments separated by dots. The header and payload are not encrypted — just encoded — so they can be read by anyone.
Paste a token to see its decoded header and payload, with issued-at, not-before and expiry timestamps converted to readable dates (and flagged if expired). Decoding happens locally and the token never leaves your browser.
Frequently asked questions
No. It only decodes the header and payload so you can inspect them. Verifying the signature requires the signing secret or key and must be done server-side — never trust an unverified JWT for authorization.
Decoding runs entirely in your browser and nothing is uploaded. Still, treat live tokens as sensitive — anyone who sees a valid token can use it until it expires.
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