JWT Decoder
Paste any JWT and this tool decodes its header and payload into readable JSON, and highlights standard timestamp claims like expiration — all without ever sending your token anywhere.
How it works
A JWT is three base64url-encoded segments separated by dots: header, payload, and signature. This tool splits your token on those dots, decodes the header and payload back into JSON, and displays the signature as-is.
Tip
Well-known claims like exp (expiration), iat (issued at), and nbf (not before) are Unix timestamps in seconds — this tool automatically converts any of them it finds into readable dates.
Does this verify the token is authentic?
No. This tool only decodes the token's contents — it does not verify the signature. Anyone can craft a JWT with any header and payload they like; a token that decodes cleanly is not proof it was issued by a trusted server or hasn't been tampered with. Signature verification requires the secret key or public key used to sign it, which this tool never has access to.
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