Phone apps that use black instead of white use less battery life

We now have proof that apps drain less of your phone’s battery life when they use darker colors, like black and gray.

At a recent Android Dev Summit session (via SlashGear), Google revealed what we’ve long suspected: the colors used within apps have a direct impact on smartphone battery life, and white or brighter colors are a bigger drain.

Using an original Pixel phone, Google tested various ways the phone was draining battery life. Brightness was of course one of the most obvious factors; everyone knows that the brighter you set the screen to, the faster your battery depletes.

However, the most informative news from the session concerns the use of color. As many of us tech geeks who are already well-versed in the technicalities of a phone’s display already know, switching on a phone’s night mode (if it has one) helps conserve battery life.

While not as noticeable on phones with LCD screens where the entire display is backlit, the power savings from phones with OLED displays (i.e. Samsung phones, Pixels, iPhone X, XS, XS Max, etc.) is considerably greater.

This is because OLED screens aren’t backlit like LCDs, with a uniform level of brightness lighting up all the pixels. Instead, each pixel in an OLED display has an on and off state. As such, the pixel only turns on and uses power when it’s any color other than black. A black pixel is “off” and that’s why blacks are so deep on OLEDs compared to LCDs — because they’re not even lit up.

So it really shouldn’t be surprising that apps toggled to night/dark mode, which often use more black or dark gray, will reduce the speed at which your phone’s battery drains.

I encourage you to switch to night mode (where available) not just because your phone will last longer, but because it’s easier on the eyes. Twitter with a dark theme is less blinding than a day theme that’s mostly white, especially when you’re looking at it in the dark or in places that aren’t bright (like bars, restaurants, etc.).

Google, for its part, hasn’t exactly helped conserve battery life on Android with the Material Design-ification of all of its apps, though. In its attempt to create a consistent and modern flat UI for across all of its apps and services, Android app creators went overboard with the white “negative space.” As a result, their apps suck up more power than they need to.

The takeaway for Google and Android app developers is simple: Use more black and darker colors. It’s good for saving power and dark mode looks so much better in my opinion.

But it’s not just Android phones that can benefit from embracing black in apps. iOS developers should do this as well. With the iPhone X, XS, and XS Max all using OLED screens, there’s an opportunity to make good-looking apps that are also good for battery life.

As someone who’s been using dark mode wherever possible in apps like Twitter and Apollo, and using a black wallpaper on my homescreen, I constantly wish more apps embraced the aesthetic. Now that there’s proof it actually prolongs battery, there’s even more reason to make dark mode an option.

If Apple steps up and takes the lead with dark mode in its default iOS apps, it’ll incentivize other app developers to follow suit. Apple’s already taken baby steps with dark mode on macOS Mojave and it’s glorious. 

It’s time the company did the same with iOS. It’s always seemed strange to me that some iOS apps are dark (i.e. Clock, Watch, Compass, Activity, Calculator) but others aren’t. Maybe in iOS 13 Apple can finally dark mode all the apps. If there’s one thing iOS 13 should have, it’s this.