Big MFA

Secure TOTP/HOTP authenticator with encrypted vault, QR import and offline MFA code generation.

Big MFA is a secure, privacy-focused authenticator for managing TOTP and HOTP two-factor authentication codes directly in Chrome. Your MFA accounts are stored locally in an encrypted vault protected by your master password. Big MFA is designed to work offline for code generation, helping you keep control of your authentication secrets without depending on a cloud service. MAIN FEATURES • TOTP and HOTP authentication codes • Support for SHA-1, SHA-256 and SHA-512 • 6-digit and 8-digit OTP codes • Secure encrypted local vault • Master password protection • QR code import • Google Authenticator migration import • Encrypted backup and restore • Account renaming and management • Offline MFA code generation • Multi-language interface • Support for 50 languages PRIVACY AND SECURITY Big MFA is designed with a local-first approach. Authentication secrets are kept in the browser's local storage in encrypted form and are not required to be sent to an external cloud service for OTP generation. The encrypted backup format uses modern cryptographic protections, including AES-256-GCM and password-based key derivation. Big MFA has also undergone automated and manual security and quality testing, including unit tests, static analysis and integrity verification of the production package. OPEN SOURCE Big MFA is distributed under the GNU General Public License version 3 (GPLv3). IMPORTANT Big MFA helps you manage two-factor authentication credentials. Always keep a secure encrypted backup of your accounts before deleting or replacing an authenticator application or device.