Honest note: real verification requires the secret, and a signature can only prove the token was signed with it. This page runs entirely in your browser; your secret is never sent anywhere.
Frequently asked questions
Does this tool send my secret to a server?
No. Signing and verification run with the WebCrypto API inside your browser. Your secret never leaves this page.
Can I verify a token without the secret?
No, and no tool honestly can for HS256. Decoding the header and payload works without the secret, but checking the signature requires it.
Is a valid signature proof the token is safe to trust?
It only proves the token was signed with that secret and has not been altered. You should still check the payload claims like expiry yourself.
Preview
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