Free online TOTP generator, no installation required, compatible with Google Authenticator, supports Time-based One-Time Password (TOTP) generation;
- Secret Key: Must be valid
base32
encoded, 16~128 characters in length; - Generate Random Key: Creates a random 64-character key;
Uses HMAC-SHA1
algorithm for hashing, generates 6-digit codes with 30-second time windows;
TOTP Principles
TOTP (Time-Based One-Time Password) is a dynamic password generation algorithm widely used for two-factor authentication (2FA), defined by RFC 6238. It can generate time-changing one-time verification codes without requiring network connectivity;
TOTP workflow:
- Shared Secret: A base32 encoded secret key is pre-shared between user and server;
- Time Counter: Current Unix time (in seconds) divided by fixed time step (typically 30s) to get counter value;
- HMAC Calculation: Uses HMAC-SHA1 algorithm with secret key and time counter as input;
- Truncation: Extracts 4-byte portion from hash result, converts to integer, then mod operation generates fixed-length code (typically 6 digits);
Using Google Authenticator
Google Authenticator is a free two-factor authentication (2FA) app provided by Google to enhance account security. It generates one-time passwords (OTP) as secondary verification for logins, commonly used to protect Google, Facebook, GitHub, Dropbox and other accounts.
- Open Google Authenticator app;
- Tap the
+
button at bottom right; - Select Enter a setup key;
- Enter details:
- Account Name: Service name
- Key: base32 encoded (can be generated on this page)
- Key Type: Time-based
- Click Add;
After adding, it will automatically generate 6-digit codes that refresh every 30 seconds;