On the YouTube channel PhoneBuff conducted a curious study that aimed to find out how working with an active dark theme is better for the battery of the device than in a traditional light one.
Dark theme in iOS 13 saves battery:
The iPhone XS was used as a test device. This smartphone performed various tasks in iOS in light and dark mode. The Messages app, navigating Google Maps, watching YouTube videos, and other tasks were used.
The final result really surprised. Tests showed that using the dark mode iPhone XS discharged the battery much more slowly than the same device with a light theme. On both smartphones, the brightness was set at 70%. After two hours of "Messages", the iPhone XS with a dark theme has 88% of the battery, and the smartphone with a light theme-83%. As a result, the first iPhone XS with a light theme was discharged, but the iPhone XS with a dark theme had another 30% charge.
On which iPhone models does the dark theme save battery power?
The effect of dark mode on the battery life of the iPhone extends only to devices with OLED displays: iPhone X, XS, XS Max, 11 Pro and 11 Pro Max.
iPhone XR or iPhone 11 and other older models with IPS-screen will not have a significant difference in consumption between dark and light mode – the backlight always works, regardless of the theme of the system.