As always, remember that the iOS 26 beta is... a beta. So, back up your phone before making the switch. And as Apple says in its Beta Program FAQ, "Beta software may contain errors or inaccuracies and may not function as well as commercially released software. We encourage you to submit feedback when you encounter these issues.

Apple has confirmed iOS 26’s public launch this fall, following the release of beta 4 to developers and testers with major UI and Apple Intelligence updates.

Looking at the home screens, the primary difference you'll find is that in iOS 26 the background of the dock and the search option that sits in between the dock and the home screen icons are more transparent and have a sheen to the edges, whereas in iOS 18, these are slightly darker.