I don't know about Windows, but if you see the example your Mac is putting it in your keychain app, which is usely available on other devices that are connected to your Apple account. Also if you install a new macbook. Most likely also on your iphone. If you have an Android phone that will be a lot less smoot

I had the impression that Apple stores and syncs them for you, but at no point will give you the option to actually backup or restore (have a copy of the info under your management). Let's say I need to move a credential from my account to my wife's, I guess it's probably not allowed. Or god forbid I change Apple IDs.

You can export your password (from Safari or from the Settings app) to a csv file. Not sure how that handles passkeys, if at all, however. Probably not (yet).

You can set up as many as you want, so just register your phone as one and your PC as other. Eg. using Windows Hello. If you loose or compromise one device, you just delete it as a passkey - rest is still working. If you loose all of them at the same time somehow, there's usually fall back to password or some kind of reset process.

For every account thought, correct?

Like, I can keep all my passwords in a password manager. And then copy and replicate that database however I want to.

With passkeys, I'd need to set up and authenticate additional devices... for every of hundreds of accounts I have? Am I wrong? Like if I have an android tablet and iPhone and windows PC and a Linux PC (as I do) that's half a dozen setups for each and every account? And this is a good thing??

It's my understanding that passkeys that are created by platform authenticators or password managers can be backed up. That's how replicating your key through iCloud likely works. Hardware keys on the other hand don't support backups by design. You need to enroll multiple keys to have a backup.

> With passkeys, I'd need to set up and authenticate additional devices

This is true, if you don't use a platform authenticator or password manager and only use hardware keys.

As mentioned by other you can use solution, that propagates your passcode credentials across devices - probably most password managers will offer this soon. I wouldn't, because you loose separation in case of compromise of one device, but if you do - it's still on par with security level of today's password managers with cloud sync.

Also you don't really have to set up everything everywhere all at once - passwords still work and you can use phone passkey on PC via QR.

> I've spent about 10 minutes Googling, and I'm still not sure how I backup and restore passkeys.

In the Apple ecosystem your passkey is / can be sent to your iCloud Keychain, which you can restore when you can a replacement device (and keep using on non-lost/stolen devices):

* https://support.apple.com/en-ca/guide/iphone/iph82d6721b2/io...

* https://www.google.com/search?q=apple+passkey+icloud

This doesn’t address the issue if OP needs temporary access via an Android device.

If you still have access to a device that can handle the passkeys then you can use the scan of a QR code to gain access.

If you do not have access to a device with your pass key on it then using iCloud Keychain is probably not the best service to use for your use case of an Android device. Use one of the many other services that also provide Android support and passkey support. Then you can access that service and access your passkeys.

iCloud is one of many. Bitwarden and 1Password will both support passkeys, both have Android support.

Yes, Bitwarden's pass key support is for "this summer".

https://bitwarden.com/blog/bitwarden-passkey-management/