TOTP 2FA Code Generator

How to Use the TOTP Generator

To use the TOTP Generator, follow these steps:

1. Paste your Base32 secret key into the provided field. You can find this key in your 2FA setup page, usually shown as a text code below the QR code.

2. Watch the live TOTP code display. A 6-digit code appears and updates automatically every 30 seconds.

3. Match the settings (digits and period) to match your service's configuration. Most services use 6 digits and 30 seconds.

4. To verify a code, switch to Verify mode and enter the code you want to check. Ensure your device's time is synchronized to avoid clock skew.

When to Use the TOTP Generator

Use the TOTP Generator when you need to set up two-factor authentication (2FA) for a service that requires it. This includes popular services like Google, Facebook, and Twitter.

The TOTP Generator helps you generate and verify TOTP codes, ensuring secure access to your accounts.

How It Works

The TOTP Generator uses the Time-based One-Time Password (TOTP) algorithm, defined in RFC 6238. Here's a simplified explanation of how it works:

1. The current Unix timestamp is divided by the period (30 seconds) to get the time counter T.

2. HMAC-SHA1 is computed using the shared Base32-decoded secret key and the time counter T.

3. The last nibble (4 bits) of the HMAC is used as an offset to extract a 31-bit integer from the HMAC starting at that offset.

4. The extracted number is taken modulo 10^digits to get the final code (padded with leading zeros if needed).

Tips, Edge Cases, or Limitations

1. Ensure your device's time is synchronized to avoid clock skew issues.

2. Use only uppercase letters A-Z and digits 2-7 for the Base32 secret key.

3. Most services use 6 digits and 30 seconds for TOTP, but some enterprise apps may use 8 digits or 60-second periods.

4. For related security tools, consider using the HMAC Generator, Password Hasher, and Base64 Encoder.

Quick reference