I have a friend who is very particular about things. She takes her coffee a certain way, eats a certain way, and uses her phone a certain way. She, like many of us, is concerned about battery life on her phone. She, like many of us, is concerned about performance. So, she, like many of us, double-clicks her iPhone’s home button when she’s done with an app swipes it away to close it. She, like many of us, thinks this helps battery life and performance. And she, like many of us, is wrong. Dead wrong.
Breaking the habit
Both iOS and Android offer ways to multitask though apps. iOS uses a gesture or double-click of the home button and Android has a dedicated button in the navigation bar. Both also offer a very satisfying way to close open apps by swiping them away. The idea is that you can open your multitasking view to see which apps are open and swipe away the ones you aren’t using. You feel warm and fuzzy inside from satisfyingly flinging away an app you no longer need and the operating system frees up memory and CPU resources for other tasks.
In theory this all sounds nice but it doesn’t actually work this way.
iOS handles multitasking by splitting apps up into the foreground and background. As you can imagine, the foreground is any app that is open on your screen and is currently in “focus”. Apps not in focus fall behind the open app and are in the background. Some background apps do continue to use system resources – active map applications (navigation, for example) and music apps continue to give you directions and play music even when not in focus. All other background apps in iOS that are not providing the user with an ongoing process are essentially frozen. Their current state is saved into RAM and are effectively not allowed to continue running any new process.
Android used to handle multitasking differently. In prior versions (6.0 Marshmallow and older), Android had very little restriction on what a background process could do. Sure they lost “focus” and therefore couldn’t carry out any more operations, but they could continue to use GPS, RAM, CPU, and GPU resources. This caused apps that were coded poorly or maliciously to continue to eat away at available resources and steal them from foreground apps. This is part of the reason why Android gets the reputation of being slow and inefficient.
Google changed background restrictions on apps starting in 7.0 Nougat and further refined them in 8.0 Oreo to look more like iOS’ handling of apps. Foreground apps have focus, background apps (unless running media or maps, etc) fall out of focus, are frozen and left to wait to be recalled.
Resist the urge to swipe
An app that is opened and then frozen in the background uses up a lot less operating system resources and memory than an app that was opened, swiped closed, then reopened. Every time an app is resumed from its frozen state, the operating system already has resources allocated to 1. keeping it frozen and 2. resuming it from its last-used state, so it doesn’t have to go through that process again. It’s kind of like driving a car.
When you’re driving around, you’re using resources (fuel) to move you from place to place. When you come to a stoplight, your car is not moving, but the engine is still on an idling. While idling, your car is still using fuel, but not as much as if it was actively driving. The light turns green, you step on the accelerator and you’re off.
Now imagine coming to a stoplight and turning the car completely off. Imagine doing that every single time you came to a stoplight. The amount of wear and tear and fuel that you’d use is much higher than just letting the engine idle but keep running.
Similarly, closing an app by swiping it away forces the system to have to clear its processes from memory and completely start from scratch when you call it up again later. This uses a ton of CPU, RAM and battery resources that didn’t need to be wasted. This results in poorer CPU performance and reduced battery life, not to mention unnecessary wear and tear on your internal components.
So unless you’re using an app that you plan on using once and not again for a long while, follow the advice of the Beatles and don’t swipe away your apps – just let it be.