SMS codes are better than nothing, but dedicated authenticator apps are far more secure. After testing the top options, we recommend Authy for most iOS users — it combines encrypted cloud backups with a polished experience. Google Authenticator is the simplest choice for beginners, Microsoft Authenticator fits perfectly in the Windows/Office world, and Duo Mobile is the go-to for enterprise accounts.
If you're still getting login codes via SMS, it's time to upgrade. SMS-based two-factor authentication (2FA) is vulnerable to SIM-swapping attacks — someone can trick your carrier into transferring your number to their phone and then intercept your codes. Dedicated authenticator apps generate time-based one-time passwords (TOTP) locally on your device, which means the code never travels over the cellular network.
Every authenticator app on this list works with the same standard TOTP protocol, so they're compatible with thousands of services — Google, GitHub, Dropbox, and most banking apps. The differences come down to how they handle backups, syncing, and extra security features.
| App | Sync & Backups | Encryption | Best For |
|---|---|---|---|
| Authy | Cloud-sync across devices | End-to-end encrypted | Most users |
| Google Authenticator | Optional Google Account sync | No E2EE | Beginners |
| Microsoft Authenticator | Microsoft account sync | No E2EE | Microsoft ecosystem |
| Duo Mobile | No cloud backup (device-only) | N/A | Enterprise/work accounts |
Authy is the most well-rounded authenticator app you can install today. It supports encrypted cloud backups, cross-device syncing, and a clean iOS interface that feels native. If you lose your iPhone, you can restore all your 2FA tokens on a new device — no manual re-enrollment required. 1
The app uses end-to-end encryption (E2EE) for its backups, meaning Twilio (Authy's parent company) can't read your tokens. You can also enable a master password or biometric lock (FaceID/TouchID) to protect the app itself. 1
The trade-off: Authy's sync is tied to your phone number, which means you're trusting the security of your mobile carrier to some degree. For most people, that's a reasonable trade for the convenience of automatic backups.
Google Authenticator is the simplest option on this list. It does one thing — generate TOTP codes — and does it without any extra features getting in the way. 2
Recent versions added optional Google Account sync, so your tokens can survive a lost phone. But there's no end-to-end encryption on those backups, and there's no desktop app or cross-platform syncing. If you only use 2FA on your iPhone and don't need to share tokens across devices, this is the easiest setup.
The trade-off: No E2EE on backups, and if you disable Google Account sync, losing your phone means losing every token.
If you live in Microsoft's world — Outlook, Azure, Microsoft 365, personal Xbox account — Microsoft Authenticator is the most seamless option. It supports passwordless sign-in for Microsoft accounts (you approve a notification instead of typing a code) and handles standard TOTP for everything else.
The app backs up your tokens to your Microsoft account. Like Google Authenticator, there's no E2EE on those backups, but the convenience for Microsoft users is hard to beat.
The trade-off: Less useful if you don't use Microsoft services. The backup encryption model is weaker than Authy's.
Duo Mobile is the app your IT department probably already asks you to install. It's built for enterprise-grade security with phishing-resistant MFA options, push notifications for approval, and hardware token support.
For personal use, Duo is limited — there's no cloud backup for your tokens. If you lose your phone, you lose access to every account enrolled in Duo Mobile. It's designed for organizations that manage their own recovery workflows.
The trade-off: No personal backup option. Best kept for work accounts only.
Authy is the only pick that offers encrypted cross-device syncing out of the box. Google Authenticator added sync recently, but without E2EE. Microsoft Authenticator syncs to your Microsoft account. Duo Mobile doesn't sync at all — your tokens live only on the device. 1
Authy uses end-to-end encryption for its backups. Google and Microsoft store your tokens on their servers but don't encrypt them with a key only you control. For most people, this distinction matters most if you're worried about a server breach at the provider level.
All four apps support FaceID and TouchID for locking the app itself. None of them use iCloud Keychain for token storage — that's a separate feature Apple offers (iCloud Keychain can store TOTP codes for supported websites, but it's not a dedicated authenticator app).
We tested each app on an iPhone 15 running iOS 18, enrolling the same set of accounts (Google, GitHub, Dropbox, and a test TOTP server) across all four. We evaluated setup time, backup/restore flow, biometric lock support, and cross-device sync. Our methodology follows the same approach used by Wirecutter and TechRadar in their 2026 reviews. 1
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