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2FA Authenticator

A secure, TOTP Authenticator. Generate two factor verification codes entirely in your browser without transmitting your secrets to a server.

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How Client-Side 2FA Works

Time-Based One-Time Passwords (TOTP) power the 2FA systems used by Google, Microsoft, GitHub, and most major platforms. The algorithm relies entirely on two factors: the current Unix time, and a secret Base32 string provided by the platform.

The Security Advantage

Because the mathematical hash is purely formulaic, RapidCalc does not need to send your secret keys to a server to generate your 6-digit codes. The entire operation runs locally inside your browser tab.

For logged-in users, your secret keys are secured using AES-256 Client-Side Encryption. Your Master PIN is the encryption key. The browser only stores scrambled ciphertext, ensuring that even if your device is compromised, the keys remain completely unreadable without your exact PIN.