A radically simple, premium, and 100% client-side Time-Based One-Time Password (TOTP) generator. Designed with state-of-the-art glassmorphism aesthetics, Fast Authenticator keeps your two-factor authentication keys completely secure by calculating them directly within your browser. No servers, no tracking, zero databases, and fully functional offline.
- 🛡️ 100% Client-Side Web Crypto: Cryptographic signatures are calculated locally using the browser's native Web Crypto API (
window.crypto.subtle) for sandboxed, secure execution. - 📱 Adaptive Overlay System: Sleek floating cards on desktop viewports and smooth sliding bottom-drawer sheets on mobile screens running at a locked, GPU-accelerated 60 FPS.
- 📂 Flexible Entry Formats:
- Camera QR Scanner: Scan visual codes via integrated camera access.
- Upload QR Image: Drag and drop or browse standard images (PNG, JPG) containing codes.
- Manual Entry: Save accounts with customized issuers, labels, and advanced settings.
- List Import (Bulk): Paste raw Base32 secret keys line-by-line to add multiple keys instantly.
- ⏳ Upcoming Code Preview: Displays the upcoming code directly underneath the active one, allowing you to copy not only the current OTP but the next token with a single click.
- 💾 Local Data Portability: Save accounts directly in your browser's local storage. Easily export and import your saved accounts as standard JSON backup files, or wipe all device data securely with double-confirmation dialogs.
- 📲 Installable PWA & Offline Support: Fully compliant Web App Manifest and Service Worker implementation, allowing you to install the application natively on iOS/Android and run it entirely offline.
- 🌐 Insecure Context Fallback: Automatic, silent fallback to a custom, pure JavaScript cryptographic engine (SHA-1, SHA-256, SHA-512) and fallback clipboard operations if hosted in HTTP or local development server environments.
- Core: HTML5, Vanilla JavaScript, CSS custom variables
- Cryptography: Web Crypto API (
window.crypto.subtle) - Webcam Scanning:
html5-qrcode(lazy-loaded dynamically only when camera or upload features are triggered) - Caching: PWA Service Worker caching static assets and Google Fonts
- Aesthetics: Glassmorphic backdrops, harmonious HSL dark/light modes, micro-animations, and Outfit/Plus Jakarta Sans typography.
Important
Your keys never leave your browser context. Since Fast Authenticator is static and serverless, there are no endpoints, cookies, logins, or tracking pixels to compromise your data.
- HMAC calculation is completely sandboxed.
- Service Worker operates as a local proxy, guaranteeing offline functionality.
- Important Storage Warning: Browser
localStoragestores secrets unencrypted. Make sure your device profile or operating system is password protected, and avoid using the app on shared public profiles.
Simply visit 2fa.fast (fully secure HTTPS context) to start generating codes instantly.
Fast Authenticator is built as a single, self-contained HTML document. You can run the app offline on your computer without running a web server:
- Clone this repository or download the ZIP:
git clone https://github.com/yuriionline/2fafast.git
- Open
index.htmldirectly in any web browser. - Add your keys to begin generating codes locally.
To quickly pre-load a temporary account, copy a code, or save a token, append the raw Base32 secret key directly to the URL:
https://2fa.fast/?YOUR_SECRET_KEY
This loads a temporary preview card on the main page, automatically copies the generated code, and provides a one-click button to save it persistently on your device.
Fast Authenticator supports the full range of standard Authenticator algorithms and parameters:
| Parameter | Supported Options | Default |
|---|---|---|
| Algorithm | SHA-1, SHA-256, SHA-512 | SHA-1 |
| Digits | 6 digits, 8 digits | 6 |
| Period | 10 seconds to 300 seconds | 30 |
This project is licensed under the MIT License.