Automatic dark and light mode theme switching has been a built-in feature in macOS, Android, iOS, and even many Linux desktop environments for a good while, but has been lacking in Windows. Now, it appears automatic theme switching will come to Windows 11 in an upcoming Insider build, as spotted by @phantomofearth on X, who shared strings from a recent Experimental Windows build. These strings are accompanied by a new DLL, "Windows.Shell.AutoDarkMode.dll," in the System32 files.

Strings include "Schedule auto mode," "Mode only changes when PC is idle," "This prevents the mode from changing while you're working or in meetings," and "Turn on location services to automatically schedule dark mode. When location services are turned off, dark mode is active from [START] to [END]." These appear to be tooltips or instructions from a settings page.

Windows 11 users will soon be able to schedule dark and light mode switching according to a custom schedule or sunrise/sunset based on location. It also seems Windows will only switch themes when the system is idle, an optional feature in KDE Plasma. It's unclear if auto dark mode on Windows will also apply a warm color filter to reduce eye strain, as with macOS.