OTP / TOTP Generator

Generate and verify time-based one-time passwords (RFC 6238) compatible with Google Authenticator and similar apps.

Secret Key (Base32)

Interval (seconds)

Digits

Enter secret →

—

Refreshes automatically

Verify a Code

Enter code to verify

How TOTP Works

AlgorithmHMAC-SHA1 (RFC 6238)

Counterfloor(Unix time / interval)

TruncationDynamic offset from last nibble of HMAC

Output31-bit value mod 10^digits

CompatibilityGoogle Authenticator, Authy, 1Password, etc.