I use the Xcode Simulator for testing and debugging the website I create on iOS since I don’t have an iPhone. It is basically the full iOS running inside a window on your Mac.

Since upgrading to macOS Sonoma I was not able to launch or create a new Simulator however. When trying to create a new Simulator I wasn’t able to click into the “OS Version” field – it just wouldn’t do anything:

How to Fix Not Being Able to Pick an OS Version

When I opened the main Xcode app and selected the “iOS” tab on top, it showed the notice “iOS 17.0 Not installed”. So just click on “GET” and download the new OS, which might take a little while:

After having downloaded the iOS version and reopening the Simulator app I could pick the “OS version” again and was able to use my old Simulators and also create a new Simulator device without a problem:

So here is this website running inside a virtual iPhone 15’s Safari. You can use almost all features of Safari and see the whole browser ui which is handy for better testing of responsive websites:

Bonus Tip: Add more OS versions inside XCode / Simulator

I also learned along the way that inside Xcode’s settings you can head over to the “Platforms” tab to see all installed Platforms and download new ones: