TOTP Generator/Verifier

TOTP (Time-based One-Time Password, RFC 6238) is a two-factor authentication algorithm that generates a one-time code from a secret and the current time. It's exactly what runs under the hood in Google Authenticator, Authy, and similar apps.

How to use it

• Generate: paste a secret key (usually Base32, the same one encoded in a 2FA setup QR code) and the tool shows the current 6-digit code along with the time left before it changes.
• Verify: enter a secret and a code from an authenticator app to check whether they match.
• Verification tolerates a small amount of clock drift — it accepts a code from a neighboring time step, not just the current one.

Common uses

• Debugging your own 2FA implementation on the backend — checking that the server generates and accepts codes correctly.
• Manually generating a code for an account when you don't have your phone with the authenticator app handy.
• Figuring out why an app's code is being rejected by the server (usually the cause is a clock out of sync).

Things to keep in mind

A TOTP code is only valid for a short window (usually 30 seconds) — that time limit is the main protection, not the secret alone.

Code accuracy depends directly on the device's clock being synced; a noticeable clock drift is the most common cause of rejected 2FA codes.