I love people explaining why you should never, not ever kill all apps on your iPhone. Except, sometimes, that advice sucks, and you totally should. So let me explain and that way it might actually make the kind of sense that does.
Most of the time. Hell, almost all the time, iOS will do a way, way better job at managing apps and multitasking resources on your iPhone than… any puny human.. could ever even dream of doing. Even using on-device intelligence — Machine Learning, algorithms — to predict which apps you’ll most want to open and when. And pre-loading them to make sure they’re primed and ready based on that bet.
Here’s how it works. When you switch out of an app, it’s supposed to save its current state and go to sleep, to hibernate. Then, when you switch back, it’s supposed to wake up, to resume from that exact same state. Right where you left off.
If you don’t go back for a long time though, or if you load up the Camera app, because Apple always wants that to be instantly available with zero shutter lag, and especially if you start taking a ton of computationally intensive photos and videos, but also if you launch a big, cross-compiled game or bloated social media app, one that sucks all the RAM out of the system, iOS will start jetsam… to jettison… the last used, least used apps from memory to make room for those greedy new RAM sucking apps.
Then… then you will have to relaunch any apps that got the boot. Often just exactly those games and social media apps. And it’s annoying. Hella annoying. But it shouldn’t happen too often, especially on more recent iPhones with more RAM.
But, that’s why everyone from Apple Support to Apple’s head of software, engineering, Craig Federighi, will tell you to never, not ever force quit all apps. Any app… unless it’s just completely frozen and non-responsive… Basically non… usable.
Because letting apps sleep and wake is just way, way more power efficient than killing and resurrecting any of them, especially all of them. Both in terms of your time, because you don’t have to go spelunking through the system and the app just to get back to where you left off, and in terms of power, because… iOS doesn’t have deal with all the overhead of you relaunching and spelunking back to where you left off. It’s just better for everyone.
And doing that with all your apps, all the time. Every time. Making it rain apps. Well, that’s not better for anyone. And doing that actually contributes to your battery drain.
So, then, why will Apple Geniuses, on occasion, famously, infamously, sometimes… just sometimes kill all apps anyway? Even tell you to do it? Even though it’s hugely controversial?
Because sometimes an app goes bad, a process goes rogue, your iPhone gets hot, your battery drains before your eyes, and rather than taking the time and going through all the effort of tracking down exactly which app is causing the problem — installing diagnostics, running tests, monitoring for days or weeks — they’ll just… kill everything. And sometimes salt the ground with a hard reset right after.
Volume up. Volume down. Press and hold the side button until you get logo. The… Konami code of trouble shooting.
And yes, sure, sometimes there are known offenders. Over the years those have included Skype, Facebook, Snapchat, Pokemon Go, Instagram. Every beta, seriously Instagram?
The more bloated, the more cross-complied, the more poorly coded, the game or social app, the higher the odds of them behaving poorly. Who could possibly have guessed?
But you can also always start by checking your Settings > Battery > Background usage, look for apps with high background usage, low foreground usage. Force quit those first. Only those. And see if that works. Only when you’re really really desperate, when you really, really can’t figure it out but you need to stop the drain and immediately, that you should even consider scorching the earth with a kill-all.
That’s why the fast app switcher lets you kill apps to begin with. But also why it doesn’t make it easy for you to kill all apps, at least not without making it rain killed apps.
It’s there for when things go wrong, really wrong, so you can fix them with a good old fashioned restart. Not all the time, not with wanton abandon, but only when you really have to. Otherwise, if you just force quit apps all willy nilly like, when you’re looking for the cause of poor performance and excessive battery drain on your iPhone, well…. that cause would be you.