Dark Mode is touted by many as a handy feature of modern smartphones that allows OLED devices to conserve battery power. This is because such displays are capable of turning off individual pixels to display black. However, a new study by American scientists from Purdue University has shown that the activation of dark mode does not matter much for power consumption in a typical smartphone use scenario.
The researchers tested six applications (Calculator, Google Calendar, Google Maps, Google News, Phone, and YouTube) using a proprietary tool called the Per-Frame OLED Power Profiler (PFOP). They examined how dark mode affects the power consumption of each of these apps on the Pixel 2, Pixel 4, Pixel 5, and Moto Z3 smartphones. It turned out that switching from light mode at 30-50% brightness to dark mode saves on average 3 to 9% energy for all tested devices. This level of brightness is used on many smartphones in Auto mode.
More significant energy savings are observed when switching to dark mode from light mode with maximum brightness. In this case, you can save 39 to 47% of battery power. The study also argues that Android does not take dark mode into account when calculating the power consumption of an app, so a tool called Android Battery + was created for this purpose, which the researchers plan to make open. They also want to add the related functionality to the AOSP.
This research is interesting because many users prefer low to medium brightness, so switching to a dark theme does not really matter to save energy.