Somehow, it has become a part of mainstream culture for iPhone and iPad users to quit all their apps in multitasking as some kind of regular tech maintenance ritual to improve battery life or speed up the hardware. An understanding of how iOS multitasking works however, shows that this is completely unnecessary to close every app in the multitasking view frequently. A 9to5Mac reader decided to ask Tim Cook for an official stance on whether he quits all his apps and if it’s necessary. Although Cook didn’t answer, Apple iOS chief Craig Federighi did with an unambiguous answer ‘no and no’ …

In the email shared with 9to5Mac, Federighi jumps in to answer Caleb’s question. The message headers have been verified for legitimacy. This is the arguably the strongest opposition from Apple executives on record in reply to the ‘quit all your apps’ superstition; Apple’s official support pages say that force-quitting should only be used on a case-by-case basis when an app freezes or misbehaves.

Apple execs reply to customer emails from time to time on various issues. At least in public, this is the first time we have seen Craig Federighi intervene and reply to an email sent to Tim Cook. Like other Apple exec emails sent to readers, Craig’s message is short but succinct. He answers the question as well as thanking Caleb for being an Apple customer.

Why does quitting all your apps have no impact on iPhone battery life?

Quitting all your apps is clearly not supposed to be a thing, as it involves laboriously swiping up on tens to hundreds of individual app windows in the multitasking view. On a technical level, most of the apps are either frozen in RAM or not running at all, the system just displays them as a history for consistency. This is why the battery life impact is negligible.

Apps that do affect battery life are only things that actually do perform background operations, things like GPS navigation, background music playback and similar. However, you only really have these running when you are using them. As such, using force quit (swipe up gesture) should generally only be necessary when an app needs a hard reset as it has glitched or got stuck somehow.

Source: 9to5mac