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History for this tool
The most recent data you entered in this tool, stored only in this browser.
Save what you type here, in this browser? Your work would go into this browser's local storage, so a refresh or a trip to another tool does not wipe it. You also get a short list of previous entries under the form, each one restorable with a click. Nothing is ever uploaded, and there is no account.
Being straight about the trade-off: anything kept there can be read by anyone who can use this browser profile, and by any script that later runs on this site. A tool page can hold a private key, a password or a signed token. Saving is convenient; it is not private.
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Your inputs and history are stored locally.
Not saved
This page forgets your work when you leave it.
About this tool
Generate time-based one-time passwords (TOTP, RFC 6238) from a shared secret, and verify a code you have been given. It shows the current code, the seconds until it rolls over and the next code, so you can compare against a device that may have drifted.Questions
- Is my secret sent anywhere?
- No. The HMAC is computed locally with WebCrypto. That said, do not paste a production secret into any page you do not control — including this one.
- Why does the code not match my authenticator app?
- First check the secret, digit count, period, and hash algorithm expected by the service. Then check both clocks: a time-based code changes when its configured period ends. The page shows the time remaining on your browser’s clock, not the remote server’s time.