Originally Posted by joemikeb
  • Cookies and extensions are unique to each device, regardless of what is checked in Settings > Apple ID > iCloud.

I just realized that assertion may not be 100% true. If I am logged onto a website on my iPhone and bring it near my Mac, the Safari, or Safari Technology Preview, the icon on the Mac's Dock changes and I can transfer the iPhone's connection including the site logon to the Mac, simply by clicking on the modified icon. That also includes data stored in cookies. I assume the cookies are synched between the devices via Bluetooth(?), but I have no idea if they are physically copied or read remotely on the other device. I do know the two logons remain synchronized.

If we knew what it was we were doing, it wouldn't be called research, would it?

— Albert Einstein