Authenticator OTP Generator

Generate TOTP/HOTP codes from a Secret Key entirely in the browser

Configure your OTP generator

Secret Key (Base32)

Mode

Digits

Algorithm

Time Period (seconds)

Auto-refresh

Time-based One-Time Password

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Security Note:

• All computations happen in your browser

• Secret keys are never sent to any server

• Clear your input when finished

1. Enter Secret Key: Paste your Base32-encoded secret key (usually provided when setting up 2FA)

2. Choose Mode: Select TOTP for time-based codes (like Google Authenticator) or HOTP for counter-based

3. Configure Settings: Adjust digits (6 or 8), algorithm (SHA-1/256/512), and period/counter as needed

4. Generate: Click "Generate OTP" to create your one-time password

5. Auto-refresh: Enable auto-refresh for TOTP to automatically update codes

TOTP (RFC 6238): Time-based One-Time Password algorithm. Generates codes that change every 30 seconds (default).

HOTP (RFC 4226): HMAC-based One-Time Password algorithm. Generates codes based on a counter value.

Algorithms: Supports SHA-1 (most common), SHA-256, and SHA-512 hash functions.

Compatible with: Google Authenticator, Microsoft Authenticator, Authy, and other TOTP/HOTP apps.