The Samsung Galaxy S7 and S7 Edge’s display resolution changes from QHD (1440 x 2560) to Full HD (1080 x 1920) following the installation of Android Nougat. The alteration comes as part of Samsung’s aim to give users more control over their device’s standby times — and as such can easily be switched back.
In Android Nougat, Samsung allows you to manually set the display resolution to one of three modes — the other being HD (720 x 1280) — so that you can prioritize visual fidelity or battery life. It’s no doubt going to be a popular addition for some people, especially those who spend little time viewing QHD media but are still affected by its toll on battery life. However, Samsung is reportedly enabling the mid-tier option (Full HD) by default.
If you want to change it back, go to your Settings menu and tap the heading named Display. On the Display page, you’ll find the aforementioned resolution options, but note that you’ll need to restart your device each time you change the setting.
The difference between viewing experience at QHD and Full HD has been debated. If you weren’t previously aware of the change, consider how your battery life and viewing experience differed following the update. If you noticed a reduction in visual quality, perhaps change it back to QHD. If you didn’t, but benefited from noticeably longer standby times, you might prefer to keep it as is.