Have we standardized a way to backup and export passkeys yet? Do websites commonly allow multiple passkeys to be registered?

The right questions. The ability to set up an alternate key in advance is functionally similar to being able to make a backup.

If I had my 'druthers:

1. You can register multiple keys, such as for different devices. Like 5-10, not two.

2. There are two categories of keys: "Regular" and "Backup/Recovery".

3. Attempting to use a Backup Recovery key prompts to user to confirm that they want to discard all regular keys and promote the backup key(s) to the new regular.

In this way, a compromised backup key can't be used secretively.

Also, can I add a backup key without having the private key with me? Ideally I would like to keep a master key in a vault, to recover compromised accounts and such, but requiring me to load the master key to create every account prevents truly secure storage.

There’s FIDO CXF/CXP: https://fidoalliance.org/specs/cx/cxf-v1.0-ps-errata-2026030...

To my understanding both Apple Passwords and the Android equivalent allow you to export passkeys to a different app (password manager), but I haven’t tried it yet.

If anyone has direct experience I appreciate to know how it was.