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.
Previously, 9to5Mac has reported on Tim Cook tipping Italian Siri ahead of time, how Eddy Cue rebutted anecdotes in Yukari Kane’s Apple book Haunted Empire, which suggested that Steve Jobs threw a pen at him amongst other instances. The emails from Apple execs phenomenon was most prevalent with Steve Jobs, who regularly replied to customer emails with short, curt, honest, responses on a variety of topics.
Thanks Caleb.
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The Facebook app proves this wrong …
Check your settings for the Facebook app and make sure it isn’t able to get your location. If so, when it’s in the background it’ll drain your battery. Check it under your privacy settings.
That was a bug (intentional or unintentional depending on your opinion of Facebook) though. So yes, killing an app that has a bug that drains your battery will save battery life. Killing an app that does not have a bug that drains your battery life will not.
I’m sure you have conducted scientific tests on this, and aren’t just following your gut. /S
A simple check of Facebook’s “background” activity time still proves the app is doing all sorts of crap behind the scenes. My Facebook background activity is generally 40-50% of the total time reported in the battery section of Settings. For instance, under the “last 7 days” tab of the battery section in settings, Facebook reported 3.5 hours on screen and 2.9 hours background. I agree with Craig’s assessment in theory, but there are obviously some apps that are abusing the background app framework.
thing is even with killing the facebook app and disabling background refresh for it, it will still eat battery life for some reason.
Apparently the Facebook app was playing silent music in the background as a trick to implement other background tasks. Other app developers have done the same thing to circumvent Apple’s restrictions on background activity.
LinkedIn is pretty bad as well.
Users are stupid. This is nothing new.
Yeah. Thanks for being judgmental. Einstein. smh
Yeah, try and tell these people it doesn’t improve battery life…
An Apple engineer has insisted to me that I need to do this.
I’ve seen a huge difference by ‘false quitting’ certain apps that appear to have background activity. I understand that many apps have zero background activity. If Apps are built respectfully they should have a bare minimum going on in the background. However, even closing stock apps like Maps and Safari helps a lot.
The article itself says that “using force quit should *generally* only be necessary”. That’s the whole problem. There are *some* apps where force quitting will definitely improve battery life because the app does do something in the background. A user just has to see an improvement once to believe it works, and there are numerous apps where it’s a fact that if they kill it there will be a battery improvement. It’s not feasible to explain to normal users how iOS backgrounding works and how some apps that use location only use it in app, others use it in the background but have a low desiredLocationAccuracy and so use little battery yet others have high use, and others just plain misbehave by playing silent audio… so I really don’t think you can blame people who do this because chances are at some point they’ve killed some app and seen better battery as a result.
“others just plain misbehave by playing silent audio” <- this. Apps aren't supposed to be allowed to do this, yet somehow they still manage to make it into the app store.
“Apps that do affect battery life are only things that actually do perform background operations, things like GPS navigation, background music playback and similar.” <– or anything that uses iBeacon tech (like the Starbucks app). Force quitting these apps cancels out some of these processes on an API level…… it does help with battery life if they use these background processes.
Ironically I’d almost like the opposite of this. I use the BBC iPlayer app extensively to stream to my Apple TV 3 and it works great. It works so well that I can still use the 6+ to check email/browse web whilst it carries on streaming in the background which is pretty outrageous for a ‘phone’
However sometimes when I start the browser/mail the iPlayer app gets kicked out of memory. I’m sure a 6s+ with it’s 2gb would help with this as I ‘never’ quit apps but an option to prevent the auto quit of an app would be a nice OS feature
Never had a battery life issue
What is Cook’s email?
tcook@apple.com
I don’t get why quitting an app in iOS would be called “force quitting”. Also, I like to quit apps I’m not using because otherwise the app switcher is cluttered and difficult to use. And in some cases (perhaps due to bugs or whatever) background apps can interfere with the system, including by using up some battery life. I do the same thing in OS/X, for the same reasons: I quit apps I’m not using instead of hiding them or merely closing their windows.
Because you are forcing processes to just end which could result in data loss. It’s why it works when an app is frozen – it ignores the normal shut down processes of the App – which would normally happen automatically after not using it for a little while. There is no concept of “quit” in ios. You use an app or you don’t use it. The system manages the rest. I believe was Apple’s intent to do this with OSX too. Starting in lion, like text edit, preview, and a few others, already do this. But undoing years of habit isn’t easy. Apple added back the dock’s “open” status indicators by default after some backlash. I still turn it off though since It’s nicer to not think about which app is open or not and just think about which app I want to use.
The app switcher isn’t designed to be an “app launcher”. That’s the purpose of the home screen. Unlike multitasking view, apps are consistently in the same place you put them, allowing you to build up muscle memory. You can get very vast at pressing home, swiping to the right home screen and tapping even without really thinking about it. You also have access to search from the home screen. The App switcher is really optimized for going back and forth between 2-3 apps in a short burst of time.
The whole point of ios was to rethink computing and for a lot of people it worked because they didn’t spend much time with desktops to learn the habits of old computing. Unfortunately, it’s hard to break old habbits – like people who keep their homescreen empty like a pc desktop even though it totally defeats the purpose of it the home screen.
Well that’s funny since it was Apple that started this.
Way to point the fingers at the wrong people. Show me exactly where Apple explicitly states closing apps helps with the battery life.
On the contray, back in 2014, a self-proclaimed ex-Genius said the same thing about battery life and closing apps in the app switcher: http://www.iphonehacks.com/2014/04/closing-apps-running-background-worsen-battery-life.html
“Frozen in memory” but still allocated. So quitting apps frees memory but does not affect battery life as those tasks are suspended.
In theory, doesn’t it use more energy? If more ram wasn’t needed and a user closes an app that they then open later the whole app needs to reinstate instead of just picking up where it left off. Larger pulls fof cellular data, more start up processes running.
How are message headers verified?
The latest facebook app is STILL an exception to this rule, even if you turn off background app refresh, location services, and notifications !! I’ve done several tests and it continues to be the case to this day (just checked). It’s annoying as hell. Can’t believe Apple is not doing more about it. So yes, you need to quit your Facebook app, always. Otherwise, follow Craig’s advice.
I disagree, I have seen several phones that with to many apps open the phone becomes unresponsive. After closing all the apps the phone works like normal again. Just like a computer if you open to many apps there is a limit as to what it can handle and once that limit is reached performance will suffer.
[TL;DR: Trust your device. It’s programmed to be economical by design. ;-) ]
It’s probably worse if done regularly. Killing an app purges it from RAM and reloading from local storage is much more expensive (in both time and energy) than just unfreezing one. Loading a simple app costs millions to billions of processor cycles and also involves the NVRAM (flash memory), its controller, and the crypto-processor (Secure Enclave). Unfreezing the same app costs a few thousand processor cycles (a context switch, an animation request for the GPU and some in-app bookkeeping). At the end of the day, these small costs add up.
As for the RAM becoming crowded issue, the OS uses pattern matching and some heuristics to choose which app to kill whenever it’s short on RAM. Killing at that moment barely affects performance of the foreground app (it takes microseconds to kill). RAM uses approximately constant amount of energy anyway, so it doesn’t make sense to free memory at a time when there’s plenty free.
As soon as an app goes to the background, i.e., it is no longer visible, the system will try to put it to sleep as soon as possible. If the app doesn’t explicitly demand background execution, e.g., limited time to finish an upload or ‘unlimited’ time to provide navigation or audio, it’s frozen after a few seconds. The CPU then wastes zero energy on it. It does remain in RAM as long as it can, but RAM doesn’t use extra energy than it always does. Navigation and audio apps (and similar kinds of background-active apps) are frozen when their job is done.
This is just one of many optimisations added to iOS (and OS X) over the years. It seems Apple prefer their devices thin and energy-intelligent. I for one congratulate them for their extensive R&D into energy efficiency.
Interesting read: https://developer.apple.com/library/ios/documentation/Performance/Conceptual/EnergyGuide-iOS/index.html#//apple_ref/doc/uid/TP40015243
Why are there so many people who aren’t software SVP giving their input, as if they know more about iOS than Apples software SVP? Either Craig is flat out lying (for no reason whatsoever) or he’s telling the truth. I’m to roll with telling the truth. BTW- this isn’t new. This was enacted in iOS 7. During the onstage keynote, they even said it was a false paradigm.
Baloney. You can go into the Settings/Battery and see what apps are using up the most battery life. And I don’t care what he said, when there is an app open in the background, it IS using up some battery life. Maybe not as much as if it was the primary open app, but something.
turn off background app refresh. stop force quitting apps. In the settings pane for this Apple even states “Turning off apps may help to preserve battery life.”
Who in the world has hundreds of open apps? I find if I have a dozen open, some apps start failing due to out of memory problems (I assume). Looking forward to getting a phone with more RAM.
I do. Well, not hundreds, but I have ≈ 80 apps and they’re all ‘open’ (since I never quit any apps myself).
It doesn’t matter if you kill an app or not, an app can be launched in the background by receiving a push notification.
Ahh, thanks you for posting this article! I’m sure it won’t stop everyone from their time wasting habit of quitting apps, but even if a few are “saved”, it was worth it!
If you want to manage your multitasking swiping away the dump ass you rarely use is highly important. They’ll clog it all up and force you to scroll for what you really want farther than you’d like. Battery life may be not impacted for getting rid of the junk apps you dont frequently use is nice.
Dump apps*
That’s like navigating the web solely through the history window and managing your history to make it easier.
Nonsense, you obviously arent following my point
Really? Facebook was showing 48% of battery usage in a 24 hour period when active, and only 14% when I quit it after using it. I tried this over a few days when I saw how much battery life it was using.
is background app refresh setting turned off?
I quit apps for having more tabs open on safari
Sometimes Safari only holds on tab other than the tab I’m viewing. Really frustrating.
iPad Air 1 :(
If ipad Pro 9.7 has 4 GB RAM, I’d buy it
Some apps like Philips Hue need to be force quit in order to get them to re-connect to the bridge when away from home, otherwise they just sit perpetually in a disconnected state.
I don’t have this issue.. have you run all the updates on your bridge? are you using the old (round) or new (square) bridge?
It depends if they work in the background etc…
Leaving the camera on certainly drains the battery – and how!
TL;DR
Well, reading article and comments, it becomes clear: technically it shouldn’t matter, but practically it does, since a considerable amount of users will have one or possibly even more apps running, where it actually does help (design or error ;) ).
On my old iPad I actually do not like this freeze feature very much – it somehow leads to the effect, that a quick jumping back and forth between e.g. email programme and browser results in them being reinitialised with every switch, which can be quite a drag – it somehow seems to be going back to the system I used to like fun on, for being ‘single user, single task’ :D.
Anyhow, battery or not, every once in a while my wife complains about our cool Bluetooth light bulbs playing up on us again, since her iPhone won’t connect to them…. Never found out if the fault of a specific app, or just the sheer number, but “kicking out” a sheer endless number of “frozen” apps so far always solved the problem – I could imagine, that whoever was hogging the BT may also have used battery life in doing so ;)
Going through the comments, you can probably compile a list of apps that you could close more frequent in order to save battery life on a day to day basis, and the rest probably can be killed on a week to week, or month to month basis (esp. rarely used apps – possibly catching up to current may be more expensive than fresh load ;) ).
Bottom line & truth to be told, in real live, the answer to the question whether sensible to kill the apps ( in order to save battery life [or generally maintain overall functionality]) really depends on your device, your apps and the way you use them :D
P.S.: Applified short and honest version from me:
Select few somewhat frequent, some less frequent, all rarely
Select few possibly extend battery life ;)
(Just mimicking original mail, not employed by, affiliated ,… Apple in any way, shape or form….)
Such nonsense, apps can request permission to run processes in the background, loading the preview images of processes in the task manager will also use more battery. Unless they use magic to do it.
Such nonsense, apps can request to run processes in the background. Also loading and displaying the additionally preview images in the task process manager will also require more battery. Unless they use magic to do it.
First off kudos to Randy for clarifying that iOS apps don’t eat your mobile device memory. Cheers.
Second it may seem like iOS apps are chewing through your battery, but there are several other reasons why this can take place.
If you go to Settings > Privacy > Location Services > System Services: This will give you access to several more features that are not app exclusive. You can check these differently if you would like, and change the mobile device settings to match more of what they want the phone to do for you. The bottom option on this page is a “Status Bar Icon”. Checking this allows you to monitor whenever the phone is sending and receiving data through one of these other outlets, which can cause your battery to drain more So you may think it’s because of an app, but it may just be “Popular Near Me”
The only apps that can send and receive data in the background are marked under the settings > battery screen. So Apple Music for example will say “Airplay. Background Activity”, or Snapchat may say “Background Activity”. Otherwise the App is not using battery while running in the background.
Although facebook is a bunch of sneaky snakes so I guess you never really know with them.
CNN app is the worst, sometimes topping the battery-use leaderboard at over 50%. I got rid of it…fake battery life.