Focus Detective is a simple app designed to help you track which app has focus. This can be helpful if the app you're using sometimes loses focus unexpectedly. For example, you may find that you can no longer type or use keyboard shortcuts until you click on the app again. You may also notice that the app window no longer appears active—for example the title and toolbar buttons are be shown in a lighter color.
This app was inspired by this MacRumors post, this other MacRumors post and this Ask Different post. While they each offer helpful suggestions for tracking down the problem, I wasn't quite happy with any of them.
- Ready to download and run. It's sandboxed, signed, and notarized.
- Full source code available if you'd prefer to build it yourself.
- Doesn't rely on Python or other tools.
- Compatible with macOS 14 or later.
- Launch Focus Detective. You can close the window or hide the application while it's running.
- Optional: Open Console, select your device in the sidebar, and click the "Start streaming" button.
- Use your computer normally until the problem occurs.
- When the problem occurs, return to Focus Detective and check the entries at the top of the list. Look for anything you didn't open yourself. One common cause of this problem is "CoreServicesUIAgent."
- Optional: Return to Console and search for the app that activated. For example, I was able to look at the logs for CoreServicesUIAgent and see some information about what might have cause it to activate. In my case, it was an app I had installed via TestFlight. This seems to be a common cause without a clear solution (other than removing TestFlight) but at least you now have more information and can file a bug report!