CalcCafe

JWT Decoder

Paste a JWT to instantly read its header and payload and see whether it has expired. Decoded locally — never uploaded.

Expires

Paste a full JWT (three dot-separated parts) to decode it.

How it works

The token's three parts are split on the dots; the header and payload are Base64URL-decoded and pretty-printed, and the exp claim is compared to the current time — locally in your browser.

100% client-side — nothing you paste is ever uploaded.

Frequently asked questions

Is my token uploaded?
No. The token is Base64URL-decoded entirely in your browser, so it's safe to inspect real tokens.
Does it verify the signature?
No — this decodes and displays the claims (header and payload) and checks the exp claim. It does not verify the cryptographic signature, which needs the secret or public key.

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