From iPhone to Android: what doesn't move on its own
Switching to a newer iPhone model is nearly automatic. Switching from iPhone to Android isn't: you're leaving Apple's ecosystem, and several things you took for granted stay on the other side.
In short: contacts, photos and your calendar move over fairly easily. What lives inside Apple's own services — iCloud Keychain, the passkeys saved there, iMessage — has no direct route to Android. You have to check it account by account.
What happens
Google offers an app built for this jump that helps move contacts, calendar, photos and videos, and finds the free apps you already had on the iPhone in the Play Store. That covers the "visible" part. The part that affects your digital recovery is different: if you kept your passwords and passkeys in iCloud Keychain, those passkeys only exist within Apple's ecosystem. Apple syncs passkeys between your own devices through iCloud Keychain, but there's no route for those specific passkeys to show up on an Android: you'll have to create a new passkey (or another sign-in method) for each account, from the Android itself.
On top of that, there's iMessage: if you had it turned on, your contacts with an iPhone may keep sending you messages that way after the switch, without them reaching your Android, until you cancel that association. And then there are the authenticator and WhatsApp, which have their own transfer logic.
Why it happens
Because iCloud Keychain and the passkeys it stores are an Apple service built to move between Apple devices, not between manufacturers. And because your iMessage number stays registered on Apple's servers until you deregister it, regardless of which phone you use now. Apple has no obligation or business incentive to make its services work just as well on Android: it designed Keychain to be convenient within its ecosystem, not to be portable outside of it.
Who it hits hardest
People who used iCloud Keychain as their only password manager (not a multi-platform dedicated one) and find out, account by account, that they have to set up sign-in again. And people who didn't know iMessage had to be cancelled separately: for days they think some contacts have stopped writing to them, when in reality those messages keep arriving in an Apple inbox they no longer check.
It also hits people who had several Apple devices (an iPad, a Mac) signed into the same account: those devices will keep the full Keychain even though the phone is now Android, which can act as a temporary bridge while you reorganize your passwords, but doesn't replace having them accessible from the new phone too.
What to check before you switch
- Do you use iCloud Keychain as your only password manager, or a multi-platform one (Bitwarden, 1Password, Proton Pass…)?
- Do you know which accounts have passkeys saved only in iCloud Keychain?
- Do you have iMessage turned on, and do you know you need to deregister it for that number?
- Have you already checked the WhatsApp, authenticator and eSIM pages for this same switch?
If it already happened to you
If you're already on Android and missing passwords or passkeys you only had in iCloud Keychain, you can still look them up from a browser signed into your Apple ID at iCloud.com and copy them by hand wherever you need them; for passkeys there's no copy, only re-creating access to that account from scratch through its official recovery path. If you stopped receiving texts or calls from contacts with an iPhone, it's iMessage: Apple has an official process to deregister your number from that service.
You don't need to solve everything the first day. Prioritize the accounts you care about most (email, bank, password manager) and work through the rest calmly over the first few weeks.
Official sources: Apple: the security of passkeys · Apple: what to do before you sell, give away or trade in an iPhone