I need a two-factor authentication app that supports cloud backup and does not link to a phone number.

Finding an authenticator app that provides cloud backup without forcing you to register a phone number (like Authy does) narrows the field down to a few privacy-respecting options. Instead of proprietary servers tied to your phone number, these apps leverage your personal ecosystem's cloud (like iCloud or Google Drive) or require an anonymous account.

Top recommendations matching your criteria:

• 2FAS (2FA Authenticator)
  • Platforms: Android, iOS, Browser Extension
  • Phone Number Required: No
  • Cloud Backup: Yes. It backs up securely to your personal iCloud (on iOS) or Google Drive (on Android) using an end-to-end encrypted password that only you know.
  • Why it fits: It is open-source, requires zero registration or personal identifiers (no email or phone number), and handles cloud sync transparently through your existing device account. Learn more on the 2FAS Website.
• OTP Auth
  • Platforms: iOS, macOS, watchOS
  • Phone Number Required: No
  • Cloud Backup: Yes, it syncs and backs up via your personal iCloud account.
  • Why it fits: It is an Apple-ecosystem favorite that doesn't track usage data or require an independent account sign-up—your data stays private within your personal iCloud storage. Check details on the OTP Auth App Store Page.
• Google Authenticator
  • Platforms: Android, iOS
  • Phone Number Required: No
  • Cloud Backup: Yes, optional sync via a Google Account.
  • Why it fits: While it requires a Google account login to enable cloud syncing, it does not link to or demand a phone number for the authenticator service itself.
• Bitwarden / Bitwarden Authenticator
  • Platforms: Cross-platform (Standalone Authenticator app or integrated into Bitwarden)
  • Phone Number Required: No
  • Cloud Backup: Yes, synced securely through Bitwarden’s cloud vault or your device’s native backup (iCloud/Google Drive) depending on the specific app mode you use.
  • Why it fits: Bitwarden requires an email address to make an account (no phone number), and their zero-knowledge encryption ensures your 2FA seeds are safely backed up in their cloud. Explore the tool via Bitwarden Authenticator.

Are you looking for an app primarily for Android or iOS , and do you prefer syncing through your device's native cloud (iCloud/Google Drive) or an independent encrypted account?

Based on your requirements — cloud backup + no phone number linking — these are the best fits:

My recommendations:

1. Best overall: Proton Authenticator — closest match to “cloud backup without a phone number.”
2. Best privacy-focused choice: Ente Auth — encrypted sync and open-source approach.
3. Best if you want maximum control: Aegis (Android) — keep your own encrypted backup wherever you choose.

I would avoid Authy for this specific requirement: although it has encrypted cloud backups, creating an Authy account requires a phone number.

One security tip: whichever app you choose, keep your services’ 2FA recovery codes in a separate secure location. A cloud backup protects against losing your device, but recovery codes protect against losing access to the authenticator itself.

Yes. My top recommendation is Ente Auth.

• Ente Auth — Free, open source, and available on iPhone, Android, Windows, Mac, Linux, and web. It provides end-to-end encrypted cloud backup/sync. Importantly for your requirement, Ente Auth can be used without an account, and its account-based setup does not require a phone number.
• 2FAS Auth — Another strong choice. It explicitly says it doesn't use or want your phone number, and it supports cloud backups through Google Drive/iCloud.

What I'd choose

Ente Auth if you want the best combination of:

• No phone-number requirement
• Encrypted cloud backup
• Cross-platform access
• Open-source software
• Strong privacy

If you're Android-only, Aegis is also excellent, but its backup system is primarily file-based rather than built-in cloud synchronization.

One important distinction: cloud backup is only useful if you can recover the encryption/account credentials. I'd keep the authenticator's recovery information and your individual services' emergency backup codes somewhere secure and separate.

Finding a two-factor authentication (2FA) app that supports cloud backup without forcing you to link a phone number or register a traditional profile narrows the field to a few privacy-respecting options.

The best options available that fit your exact requirements:

• 2FAS (Two Factor Authentication Service)
  • Phone Number Required: No. It requires no account creation , email address, or phone number whatsoever.
  • Cloud Backup: Yes. It provides end-to-end encrypted (E2EE) cloud backups by syncing directly to your personal iCloud (on iOS) or Google Drive (on Android). Because it uses your existing personal device cloud storage, the app itself never collects your personal identity or phone number.
  • Platform: Mobile (iOS/Android) with browser extensions available.
• Ente Auth
  • Phone Number Required: No. You can sign up using an email address only.
  • Cloud Backup: Yes. It offers fully open-source, end-to-end encrypted cloud backups and cross-platform synchronization (mobile and desktop). While it does require an account (email-based) to sync to their zero-knowledge cloud, it never asks for or links to a phone number.
• Proton Authenticator
  • Phone Number Required: No. Like the rest of the Proton ecosystem, you can create a free account using just an email address (or anonymous recovery phrase).
  • Cloud Backup: Yes. It features end-to-end encryption, open-source transparency, and online syncing across devices tied strictly to your Proton account credentials rather than a cellular phone number.

If you'd like to narrow this down, let me know:

• Do you prefer using your own personal cloud (iCloud/Google Drive) via 2FAS or an independent encrypted sync service like Ente Auth or Proton Authenticator?
• What operating systems/devices do you need to sync between?

To get cloud backups and multi-device synchronization without tying your 2FA app to a phone number (unlike Authy), you need a privacy-respecting, account-optional, or email-account-based authenticator that features end-to-end encryption.

Here are the best options that fit your criteria:

• 2FAS (Two-Factor Authentication Service)
  • How it works: It does not require a phone number or any registration/account to use.
  • Cloud backup: It supports seamless, encrypted cloud backups straight to your own personal iCloud (on iOS) or Google Drive (on Android). The backup is locked behind a password you choose, meaning no third party can read it.
  • Privacy: Open-source, highly customizable, and requires zero personal telemetry or contact details.
• Ente Auth
  • How it works: You can use it completely offline ("Use without backups") or sign up with just an email address to enable their cloud service. A phone number is never asked for or associated with your data.
  • Cloud backup: Offers end-to-end encrypted (E2EE) cloud backups to their servers. Your vault is encrypted and decrypted locally on your device using your master password/recovery key, so Ente cannot see your secret tokens.
  • Privacy: Fully open-source and independently audited, cross-platform (iOS, Android, Desktop).
• Proton Authenticator
  • How it works: Can be used completely anonymously as a local app, or you can link it to a Proton account (signup only requires an alternative email, no phone verification mandated).
  • Cloud backup: If linked to your Proton account, it syncs your tokens across devices using zero-knowledge, end-to-end encryption.
  • Privacy: Open-source, zero-ads, and built under strict Swiss privacy laws by the Proton Privacy Ecosystem.

Would you prefer an app that backs up to your personal existing cloud storage like iCloud or Google Drive (like 2FAS ), or one that syncs via an independent encrypted account using just an email address (like Ente Auth or Proton)?

Yes. I’d recommend Ente Auth for your requirements.

Best fit: Ente Auth

Ente’s Auth app provides:

• End-to-end encrypted cloud backups and synchronization.
• No phone number requirement — Ente says an account isn't required at all; you can even use Auth completely offline.
• Apps for iPhone, Android, Windows, macOS, Linux, and the web.
• Open-source software and the ability to export your tokens, avoiding lock-in.

Another option: 2FAS

2FAS Authenticator also doesn't require an account and offers cloud/manual backup, with storage controlled by you. 2fas.com It supports iOS and Android, with browser integration.

What I'd choose

Aegis is excellent if you're on Android, but its cloud backup isn't built into an online service—it relies on Android storage/cloud-provider integration or another syncing tool.

Bottom line: Ente Auth is the strongest match if you want cloud backup + no phone number + cross-platform support + encrypted backups.

The best two-factor authentication apps that support cloud backup without requiring a phone number are 2FAS and Ente Auth . Both options avoid phone number tracking while offering secure mechanisms to recover your time-based one-time passwords (TOTP).

Recommended Apps

• 2FAS : Uses your personal cloud storage (such as Google Drive or iCloud) to store an end-to-end encrypted backup file. It requires no registration or phone number; you simply manage your sync directly through your personal cloud provider protected by a password you choose.
• Ente Auth : Requires only an email address and a master password to set up zero-knowledge, end-to-end encrypted cloud backups. It has cross-platform sync across mobile and desktop, is fully open source, and links no data to a phone number.
• Google Authenticator : Allows syncing to a standard Google account rather than a phone number. However, note that its cloud synchronization lacks default end-to-end encryption, making it less private than 2FAS or Ente Auth.

App Comparison

If you'd like, let me know:

• Whether you prefer backing up via your own personal cloud storage (Google Drive/iCloud) or an independent provider's encrypted server
• If you need desktop and browser extension support in addition to mobile

I can help you pick the exact setup that fits your security workflow.

Yes. Ente Auth is probably the best match for what you want.

• Cloud backup: End-to-end encrypted cloud backups and sync across devices.
• No phone number: Its account uses an email address, not a phone number; it can also be used entirely offline without an account if you don't need cloud backup.
• Cross-platform: iPhone, Android, Windows, macOS, Linux, and web.
• Open source: The app is fully open source.
• Security: Cloud data is end-to-end encrypted, and Ente says its cryptography has been externally audited.

Another good option: 2FAS

2FAS explicitly says it does not use or even want to know your phone number. It supports encrypted cloud backup through Google Drive on Android or iCloud on iPhone.

My pick: Ente Auth if you want the strongest combination of cloud backup, privacy, cross-platform access, and no phone-number requirement. 2FAS is excellent if you prefer your backup to live in your existing Google Drive/iCloud ecosystem.

Here are the top authenticator apps that support cloud backup/sync features while strictly not requiring a phone number to register or operate:

• 2FAS
  • Phone Number: Not required. No account creation is needed to use the core app.
  • Cloud Backup: Yes. It supports automated, end-to-end encrypted cloud synchronization directly through your own personal iCloud (iOS) or Google Drive (Android) account.
  • Why it fits: It remains completely anonymous at the app level, only interacting with your standard device cloud ecosystem if you manually turn on the sync feature.
• • Phone Number: Not required. Registration uses only an email address (you can use an alias or an anonymous/burner email).
  • Cloud Backup: Yes. It provides fully end-to-end encrypted (E2EE) cloud backups across mobile and desktop platforms.
  • Why it fits: Open-source and privacy-focused, Ente syncs your tokens securely so that not even Ente can read your secret keys, and it never asks for a mobile number.
• Aegis Authenticator (Android Only)
  • Phone Number: Not required. It is entirely offline-first by design.
  • Cloud Backup: It doesn't use a proprietary cloud, but it allows automatic scheduled backups of your encrypted vault to any local folder, which you can then sync to a private cloud like Nextcloud, WebDAV, or Syncthing using external sync tools.
  • Why it fits: The gold standard for Android privacy. It never requires any account, phone number, or email address.

Would you prefer an app that syncs natively through Apple/Google consumer cloud (like 2FAS), an independent zero-knowledge account (like Ente), or an open-source offline app where you manage your own file sync (like Aegis)?

For your requirements — cloud backup + no phone number requirement — I would look at these options:

My recommendation:

1. Proton Authenticator — closest fit:

   • No phone number requirement
   • Encrypted backups/sync
   • Available across major platforms
   • Designed with privacy in mind
     

2. 2FAS — if you prefer open source:

   • Does not require an account or phone number
   • Supports encrypted backups
   • Gives you more control over where your backup goes
     

3. Google Authenticator — easiest mainstream choice:

   • No phone number needed
   • Cloud sync is tied to a Google account
   • Less privacy-oriented than Proton/2FAS
     

I would avoid Authy for this specific use case because its recovery system is built around a phone number, which conflicts with your goal.

One extra security tip: keep your accounts’ 2FA recovery codes somewhere separate (such as an encrypted password manager or offline backup), because a backup of the authenticator app itself is not always the same thing as an account recovery plan.