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2FAS vs Duo Mobile: catalog facts
2FAS	Duo Mobile
Free Free and open source. Some components are source-available.	Free The app is free. The Duo service behind it is a paid product for organisations.
Android, iOS, Browser extension	Android, iOS
Browser extension approves codes on the phone instead of typing them Encrypted backups to your own iCloud or Google Drive account	Verified Push defeats the push-fatigue attacks that plague plain approvals Also works as an ordinary TOTP authenticator for other accounts
Mobile-first; there is no standalone desktop app Push approval needs the browser extension installed on each machine	Built around a Duo deployment that an organisation pays for Closed source
Downloadable app, Browser extension	Downloadable app
Open source	Closed source
License not stated	License not stated
Not stated if an account is needed	Not stated if an account is needed
Not stated if it works offline	Not stated if it works offline
Official website Full listing and sources Checked September 22, 2026	Official website Full listing and sources Checked September 22, 2026

Catalog facts only. Anything “not stated” is unconfirmed. Check full listings for details.