[erpellan]

Google authenticator only stores its data locally. If you lose your phone you're screwed.

Authy replicates data so you can have your 2FA on multiple devices and easily restore them if your phone dies.

[pfooti]

The funny thing is that as and end user, I can use authy to replace my Google authenticator, since it also implements the same protocol. So I use it for all my 2fa codes, mainly so I can access it from places other than my phone if needs be. I wonder if authy has monetized my use case somehow (adverts most likely).

[jbronn]

Yes it stores locally, but on iOS the data will be kept in backups if they're encrypyted.