Apple advises against this common iPhone practice
If you've been in the habit of diligently closing iPhone apps after every use, it's time to hit the brakes. According to Apple's own support page, shutting down iOS apps indiscriminately is a no-no, except in cases of a crash. And there's a solid rationale behind it.
Many iPhone users harbor the belief that shutting down apps after each use is the key to a smoother-running device or to conserve precious battery life. However, contrary to popular belief, this practice could actually be counterproductive. Apple has consistently stressed that there's little benefit to closing background applications on iOS.
The Cupertino-based tech giant has driven this point home once again in its support page detailing how to handle app closures on iOS. Alongside a step-by-step guide for users, Apple underscores that app shutdowns should be reserved solely for instances when they become unresponsive. So, when you're done with an app, simply quitting it suffices—no need to slam the door shut completely.
It's worth noting that Apple had already debunked the myth of routinely closing unused apps a few years back. In 2016, as reported by the BBC, a customer reached out to Craig Federighi, Apple's senior vice president, seeking clarity on app closures. The response was unequivocal: "No."
Blogger John Gruber underscored this crucial aspect of iOS in a 2017 post, highlighting it as a significant advantage. When an app lies dormant, the operating system freezes it, ensuring minimal consumption of RAM and processor resources. Should the user return to the app, the system swiftly brings it back to life from its frozen state.
"Apps in the background are effectively "frozen", severely limiting what they can do in the background and freeing up the RAM they were using. iOS is really, really good at this. It is so good at this that unfreezing a frozen app takes up way less CPU (and energy) than relaunching an app that had been force quit. Not only does force quitting your apps not help, it actually hurts. Your battery life will be worse and it will take much longer to switch apps if you force quit apps in the background" explains the blogger. "In fact, apps frozen in the background on iOS unfreeze so quickly that I think it actually helps perpetuate the myth that you should force quit them: if you're worried that background apps are draining your battery and you see how quickly they load from the background, it's a reasonable assumption to believe that they never stopped running. But they did. They really do get frozen, the RAM they were using really does get reclaimed by the system, and they really do unfreeze and come back to life that quickly." John Gruber adds.
Therefore, it's only natural that Apple should indicate that apps should only be closed when they crash, even if Apple doesn't give any detailed explanation.