How-To Geek

Why You Shouldn’t Use a Task Killer On Android


Some people think that task killers are important on Android. By closing apps running in the background, you’ll get improved performance and battery life – that’s the idea, anyway. In reality, task killers can reduce your performance and battery life.

Task killers can force apps running in the background to quit, removing them from memory. Some task killers do this automatically. However, Android can intelligently manage processes on its own – it doesn’t need a task killer.

Android Doesn’t Manage Processes Like Windows

Most Android users are familiar with Windows. On Windows, many programs running at one time – whether they’re windows on your desktop or applications in your system tray – can decrease your computer’s performance. Closing applications when you’re not using them can help speed up your Windows computer.

However, Android isn’t Windows and doesn’t manage processes like Windows does. Unlike on Windows, where there’s an obvious way to close applications, there’s no obvious way to “close” an Android application. This is by design and isn’t a problem. When you leave an Android app, going back to your home screen or switching to another app, the app stays “running” in the background. In most cases, the app will be paused in the background, taking up no CPU or network resources. Some apps will continue using CPU and network resources in the background, of course – for example, music players, file-downloading programs, or apps that sync in the background.

When you go back to an app you were recently using, Android “unpauses” that app and you resume where you left off. This is fast because the app is still stored in your RAM and ready to be used again.


Why Task Killers Are Bad

Proponents of task killers notice that Android is using a lot of RAM – in fact, Android stores a lot of apps in its memory, filling up the RAM! However, that isn’t a bad thing. Apps stored in your RAM can be quickly switched to without Android having to load them from its slower storage.

Empty RAM is useless. Full RAM is RAM that is being put to good use for caching apps. If Android needs more memory, it will force-quit an app that you haven’t used in a while – this all happens automatically, without installing any task killers.

Task killers think they know better than Android. They run in the background, automatically quitting apps and removing them from Android’s memory. They may also allow you to force-quit apps on your own, but you shouldn’t have to do this.

Task killers aren’t just useless – they can reduce performance. If a task killer removes an app from your RAM and you open that app again, the app will be slower to load as Android is forced to load it from your device’s storage. This will also use more battery power than if you just left the app in your RAM in the first place. Some apps will automatically restart after the task killer quits them, using more CPU and battery resources.

Whether RAM is empty or full, it takes the same amount of battery power – decreasing the amount of apps stored in RAM won’t improve your battery power or offer more CPU cycles.


When Task Killers Can Help

At this point, there are probably some people who are thinking that this isn’t true – they’ve used a task killer in the past and it’s helped increase their battery life and improve their Android phone’s performance.

This may actually be true. If you have a bad app that’s using CPU and other resources in the background, a task killer that closes the misbehaving app can improve your battery life and make your phone faster.

However, using a task killer to deal with a misbehaving app is like using a shotgun to kill a fly – you may fix your problem, but you’re inflicting a lot of other damage in the process.

Instead of using a task killer in this situation, you should identify the bad app and uninstall it, replacing it with an app that works properly. To pin down the app that’s misbehaving, you can try the Watchdog Task Manager app – it will show you which apps are actually using CPU in the background, not which apps are harmlessly being stored in memory.


Task killers can also cause other problems by killing applications that you want running in the background — for example, if you use an alarm clock app, you may find that your task killer forced the alarm clock app to quit, preventing the alarm from going off.

CyanogenMod, the popular community-developed Android ROM, won’t even accept bug reports from users using task killers, saying that they cause more problems than they solve.

In summary, you shouldn’t use a task killer – if you have a misbehaving app wasting resources in the background, you should identify it and uninstall it. But don’t just remove apps from your phone or tablet’s RAM – that doesn’t help speed anything up.

Chris Hoffman is a technology writer and all-around computer geek. He's as at home using the Linux terminal as he is digging into the Windows registry. Connect with him on Google+.

  • Published 10/25/12

Comments (38)

  1. afuhnk

    As with any ‘clearner’ app under Windows, every app needs tweaking and careful manipulation in order to work best for you.

    App designers (for Android) seems to forget how some people do not have the latest, super fast phone so they constantly upgrade their app to have more and more features and then becomes too heavy and unusable. I have a semi-decent phone (HTC Panache) and already, some apps no longer work. Even after a system wipe / factory restore their apps became too demanding for my hardware.

    I use a task manager but it’s on manual mode only and I use it when certain apps freeze or time out. I’ve made numerous tests and it does help (when the apps become unresponsive) to force close them as it sometimes took 30 minutes or Android to realise the app was bugged before shutting it down.

    More importantly, cleaning the cache helps a lot. Going into application menu and clearing the cache for all apps is a painful and extremely long task so for this I use Quick App Manager app.

  2. Marc

    Nice job. Perfectly explained. I’ve known this since the beginning but it’s nice to have an article that I can send to my friends when they argue with me about it :)

  3. James

    What about the built-in task killer on some devices?

    My GS3 allows me to hold the home button down and close any apps by swiping them, effectively killing them. My tablet also allows me to do this by pressing the “app swap” button and swipe close any app, resetting them to default upon next launch.

    Are these bad things to do as well, or is it not technically task killing?

  4. Richard

    I can go for a lot of that, and I don’t use my task-killer just because there is a lot of stuff running. But when an app starts to misbehave – not maliciously, just hangs up or gets into some state where I can’t seem to do anything – killing it seems to be a good idea. I need to check to see if my task-killer is doing anything other than sleeping when I’m not using it, though…

  5. sule

    Thanks for confirming what i heard but was doubtful. I now know that task killers are not necessary

  6. Sathish Kumar.S

    Thanks for this post, i can understand this posts deal with android operating system. yeah am using a android mobile phone, in which i used to clear the tasks which are running in the background. hereafter i wont do that. thanks once again..

  7. Cue

    I’m not convinced. I have apps that complain
    of not having enough memory which is because there are apps taking up memory and doing nothing useful
    with it. For example, killing off the camera app when I’m not taking pictures, or killing Skype when
    I’m not using it. Killing off unused applications can free enough memory to run an app that would not
    run before.

    On the literary side, you argue both sides of the point. I think a better title is “What you Need to Know
    About Killing Android Applications” and let the readers come to their own conclusions!


  8. Justin

    Unfortunately, some CPU-wasting apps come standard on some phones, and can’t be uninstalled without rooting the device.

  9. AC

    This is why my blood boils when “developers” even include Advanced Task Killer in their roms. ICS roms, even…

  10. Mick

    I have a HTC Desire and it is always running out of memory. I can’t run several large apps like Google Drive or G+ without the phone grinding to a halt. So, what is the answer for me ? Task Killer and Memory Booster seems to help when memory becomes full.

  11. nedly

    I am new to smartphones so please excuse me but I do not get this. On my Android HTC Desire S- If I have “Internet” or google open (for example) and turn the screen off, put the phone in a case on my belt, not having opened Task Manager and Killing the app(s) first my phone will be extremely warm when I take it out of the case a few minutes later. If I forget to shut the phone down and merely leave it with the screen blanked when it is not with me for a few hours the battery will be almost dead. But not so if I “Kill All” first.

  12. oscar the grouch

    My galaxy note has a task killer and it will beat up your watch dog!! My task killer is also an honor student

  13. len

    experience proves otherwise.. i have seen no instability.. only snap fast results after i kill a few programs i no longer need running in the background. I have the Samsung galaxy nexus with jellybean.

  14. dany

    Basically android is a linux system so the use of memory is what you explained, looking in the process manager in Ubuntu linux or other linux system you will see a lot of processes running related to the system functionality but you will not see application running that you have not started yet, and you will not see application running that you have already stopped. I really don’t understand why application that you use only one time a month or less should continully run in memory ( google maps, vocal search, google play store) furthermore they are impossible to kill, and when you start a new application and after using you stop it often you can see that application running in background, why don’t make application that cease running when you stop them? I don’t think it is a so big a difficulty. Sometime you will find that an application running in background is spamming your phone so the only solution is killing that application if you don’t want to remove it because it’s not replaceable. So I think the reason why most peope use task killer even when they don’t need to kill a spamming app is the fact they rightly do not understand why they should have application running they are not using.

  15. Lee Thompson

    I understand all that, but I still don’t like it. It’s the “Java” style of memory management all over again, and I don’t like it there either. (Android is Linux with Java doing the GUI layer).

    Having said that, while this different way of handling processes could work okay on paper, I’ve found in reality it’s very different. As others have noted, a lot of smartphones in particular include applications that always run, can’t be disabled or uninstalled, that leak CPU/Memory/Resources (affecting battery life, causing sluggish performance and other annoyances).

  16. pbug56

    Older Android phones came with far too little internal / working RAM (as opposed to memory used to STORE data and programs)and would actually run out at times; killing a useless task would free some up so other things could run. That doesn’t seem to be so much of a problem anymore.

  17. MikeS

    Yep – that’s what they used to say about TSR’s in DOS/Windows. Trust me, they used to say. What about the ram used up by the “paused” apps? Lots of older Android devices have very little ram to work with. When you have about 25-30 apps vying for memory, it gets tight. I don’t pretend to know, but it sounds counter-intuitive to me now, just like it did then (too long ago…)

  18. corkyjon

    I had an original Moto Droid which had low free memory and took 15 seconds to get a home page. Killing apps freed up memory and allowed it to work. Newer devices with an excess of free memory don’t need task killers, but they benefit the older phones. By the way, Google Goggles was useless, but was part of the OS,couldn’t be moved to the SD card and couldn’t be killed. I finally ditched Android for bad memory management.

  19. Willow

    So why does my (admittedly old) Legend with 2.2 come up with a warning every time the RAM drops below 10%? It doesn’t get rid of the warning itself so I find myself shutting down, or worse still, deleting apps to cope. I’m not worried about the battery life – at least I can swap them out with the legend!

  20. phynbar

    Excellent advice – how about the impact of phone virus / security apps? As guess what? That was returned as the top cpu (ab)user on my phone when I ran WatchDog for the first time….help appreciated!!

  21. grellanl

    Active task killers, “free memory” tools etc (the kind that run in the background and kill background apps) are very bad news.

    However, there’s a couple of cases where task management is useful, or even necessary – and a task manager is even built right in to the OS. Settings > Apps > Running, and you can kill services and processes.

    First, crashing or frozen apps. That’s the obvious one.

    Second comes those problematic apps that create autostart events for themselves, or that insist on running background processes for no good reason. It’s all very well to say “don’t run apps that do that” but most of them don’t give any warning or indication that they do this – and often, there isn’t a better-coded alternative available to download.

    There’s a real problem here, and unfortunately the system doesn’t give you the ability to choose which apps have your permission to run in the background. Why should a (paid) game run a 16MB constant background “billing” service, or intercept SMS messages? Why should a travel advisor app launch itself on startup and add an event to launch itself every time I connect/disconnect from a wifi network? Why should almost every app I install decide to launch itself every time I reboot the device, when I only use the app once a month? This obviously can’t scale. Simply installing an app shouldn’t have an effect on your device when it’s not running, either because you launched it or gave it permission to run in the background. Sadly, too many devs take liberties with the system and you don’t get that choice.

    The “Autostarts” tool can be useful at tracking down and managing (with root) apps that constantly load themselves without being asked to, but often you also need to check running tasks and might even want to kill them.

    Managing this is pretty much the equivalent of using msconfig to kill off a bunch of startup items on your PC. Sadly, it still requires root to really manage it properly.

  22. Citrus Rain

    I’ve had a G+ hangout that would not open. It was running, but I could not get to it.
    And since it wasn’t asking me to force close it, I had to kill it.

    You can’t “just replace” an app if it’s misbehaving. (G+ is my most used app and currently crashes quite often)

  23. Tim Tremblay

    Memory and disk storage loose performance once filled over 60%, due to lack of room for overhead. I guess if you like having things operate at half power, I guess this tip is for you.

  24. Dark Reality

    There is one universal fact about task killers: If you think they’re 100% useless, you’re either not a power user, or you are and you’ve never used an Android phone with less than 256MB RAM. Those of us who are, and have, understand why task killers are bad for Android, but also realize that Android can’t handle such low amounts (like 160MB in the Samsung Acclaim). If your phone is a beast you should never use a task killer.

  25. Holly

    Thanks for this article. I did not know any of this and am really grateful for the information. I’ll stop worrying about background-running apps! Oh, and Oscar The Grouch, you’re hilarious. Seriously.

  26. nicman23

    sry but the point of task killers is basically to use less ram which has GREAT power consumption. it is actually so big that recently (for pc) the developed a pci card to use flash memory instead of ram to consume less power


  27. Jin

    If you use task killers for RAM then do so. It will help make room for other apps that you want to stay in the background. In no way, shape, or form does a task killer harm any app or your phone. It doesn’t increase battery life, but it lets you have more control over your phone.

  28. Anon

    This isn’t always the case. Run a game and quit to home and try running aother application, depending on your phone’s spec, you definitely notice the lags and what not, due to the background game/app.

  29. m

    What about cases when you want to use your phone and you are completely unable to do so, because of the apps loading and syncing in the background? Like when turning WiFi on – second after your Android is unusable, and whole RAM is consumed.

  30. Sourav

    Thank you GTH for this wonderful explantion.
    I used to kill my background apps manually – now I won’t.

    Will pass this to my friends using Android. :)

  31. Ralph

    i’m sorry. they can SAY all they want. if I DON’T use a task killer (or a “fast reboot” widget) … the longer my phone runs, the slower it gets. I’m sorry. you can NOT convince me otherwise with all the ‘regurgitation of what they SAY is SUPPOSED to happen’. Don’t get me wrong, I LOVE LOVE LOVE my Android phones and will NEVER switch to crApple. But there’s nothing you can do to change my mind when I can tell a DRAMATIC decrease in performance the longer I go without ‘hitting that widget’ to clean things up. There are even times that when I DO hit the ‘kill task’ widget – or any other for that matter – they don’t even respond for 10-15 seconds. After that though? boom … back and going strong. So please, do explain (Samsung Galaxy S3).
    And yes, I have a widget not an ‘automated task killer’ – and I do setup what I want it to kill and what I don’t want it to kill when I hit it. Go ahead. Call me a control freak. That’s fine.

  32. Viggenboy

    Interesting, but does anyone out there know of an app that will record and log the last active app before a crash or shutdown. I thought Watchdog Task Manager would do this because I have a spurious iss with an app, which causes my phone to turn orr with some regularity, I know it’s an app be cause if I uninstall all of the apps it doesn’t do it. In stall them one by on I hear you say but, I’ve done this several times now and each time the last app installed when the bug comes back is a different one. If I could “log” the last active app my problem would be solved.

  33. nedly

    This is an extremely misleading post. In general it is more like a political document in which the author chooses only items that support his stand on the issues that are addressed. Much elaboration is missing.

  34. Myles

    With my older Lg optimus V running any ROM I had to use a task killer the phone would run out of RAM and literally restart a task killer is needed if you were like some of us who have been using Android since cupcacke on the G1 and even on Android 2.2 applications got the right to run when they want to which slowed down the phone as the applications even toke up CPU and as a result lowered battery life I highly recommend a task killer as using my Galaxy player it runs just fine with a task killer and last a long time on battery so why not try a task killer as apps can run when they want to.

  35. Rick

    I don’t use a task killer to free up memory, but there are a lot of apps out there that want to run in the background so that they can send you information updates that you really don’t care about. The Fox.News app comes to mind. I open it when I want to read the news, and it does not let you close it or shut it down. You can launch a new app, but it continues in the background sending updates to your notifcation bar that you really don’t care about. I guess I should go with the second option and just uninstall those apps that I think are misbehaving and read the web page.

  36. Lans Ellion

    I drank the “don’t use task killers” Kool-aid for a long time, but finally learned how wrong I was. I never used a task killer and always laughed at my friends who did. Finally, one of my friends showed me the speed improvement a task killer made on his phone, and after researching it I realized how necessary they are. The droid system does not work nearly as well as the idealistic developers think it does. Every app wants to run in the background and there is no such thing as a better app, they all do it. Even if they worked, the android system doesn’t leave enough open RAM for starting new applications. Sure, it leaves previously used applications in memory so you can go back to them, but most apps I use I don’t go back to for a long time. So storing that app in RAM just wastes space and slows my phone down when I try to open a new app or do something RAM intensive with another app.

    My droid 3 will grind to a halt over time so that I can barely even text. And I am a minimalist: I install almost no apps, I run no animations, I have a nearly blank home screen, etc. The only way to speed my phone back up is to kill useless background apps. I wish people would stop posting this whole don’t use task killers and would instead simply explain how to know which important system tasks you shouldn’t kill.

  37. Anibal

    Teory Practice …

    In some smartphones the task killer helps … for example so many apps that we never use are in memory …

  38. David

    I have to disagree with this article.
    Simple test. Without a Task Killer running my battery dies faster. Period.
    When I run a Task Killer, my battery lasts longer.

    If an app is truly not running, then I’m sure the OS can handle the process tree, but if a task continually asks for data then it will consume battery. The OS can’t know if I’ve requested the app to get data or if the task simply refreshes itself too often. If the app refreshes every 10 minutes (and doesn’t provide me a setting option to turn it down) then that will happen and my battery dies.

    I will continue to run a Task Killer. It works.

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