Here’s how this works: When Move to iOS requests WhatsApp data, it
gets an encrypted bundle that Apple can’t read. That bundle is
sent to the iPhone via peer-to-peer networking, like everything
else in the migration process. When a user taps on the WhatsApp
icon on the home screen on the iPhone, the app is downloaded and
installed from the App Store. When they log in to WhatsApp (with
the same phone number as the old phone), they’ll then be able to
unlock and import the transferred bundle of data.
Interestingly, the infrastructure to enable this change is already
enabled in both iOS 15.5 (the currently shipping version) and in
the current version of the Move to iOS app in the Google
Play Store. What’s changed today is that WhatsApp has flipped the
switch on the server side to allow this feature to begin rolling
out slowly, first to people opted into the WhatsApp beta testing
environment over the next week, and then eventually to everyone on
If this doesn’t sound like a big deal, think again. Until now, when WhatsApp users switched from Android to iPhone, they lost their entire message history, because there was no way to transfer it. WhatsApp is almost incomprehensibly popular worldwide — perhaps with as many as 2 billion users. It’s not a stretch to think that this alone has been keeping untold millions of Android users from switching.