[tossandthrow]

In my product we have a photo app and for normal people it is just easier to have the transferred to the phone than to use a desktop computer (without a camera) to grab a picture.

We use QR codes to transfer the user - a solution would need to be as simple as that (Ie. not requiring the user to be logged in on the same browser or other shenanigans).

The current solution is a hasle, but works well - I can't envision how a target="_mobile" should solve this? Especially since you need to transfer authentication also.

[woodpanel]

Sounds like a new product idea for services a la "login via apple-id/windows/google/...". Name it something like "send session to..."

[tossandthrow]

The issue, as also described in the comment, is that it is a hard no-go to assume that the user is logged in on the same device.

It is a shame that the family computer does not exists anymore - a place where you can't just assume that the same account is logged in on related devices.

[Asmod4n]

On windows you can “link” your phone to your windows account, or log into your Microsoft account in edge on mobile. That could solve the login part somehow.