Does Your Android Need a Task Killer App?

They were once all the rage but are they still necessary?

3D illustration of a hand reaching for a mobile phone screen

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Of all the hardware specifications listed for smartphones and tablets, battery life may be the most scrutinized. Each new generation of tablet or smartphone tends to be more capable than the ones before, with the latest features upping overall energy demands. One method that remains popular to improve smartphone and tablet battery life among some Android device users is the app killer, also known as the task killer.

Do you need one? Let's take a look.

The information and apps below should apply no matter who made your Android phone: Samsung, Google, Huawei, Xiaomi, etc.

What a Task Killer Does

A task killer is a mobile app designed to force-stop other running apps and background processes. This frees up system memory (RAM) on your phone or tablet. Some task killers perform this function automatically over designated time intervals, while others work only when the user manually chooses to kill select apps shown on a list. Many offer both options along with other customizable features.

Task killers grew in popularity as an answer to extending smartphone and tablet battery life. The premise behind using a task killer is that by removing other running apps from memory, the CPU would have less to process (activities, services, broadcasts, etc). Less work placed on the CPU leads to less energy used, which means a device would last longer throughout the day.

Despite the energy-saving claims made by task killer developers and users who swear by the benefits, there are many opposing arguments. The Android operating system has grown up over the years; it’s far more capable of managing system processes today than the earlier versions (anything prior to Android 2.2).

Not only that, but the memory inside smartphones and tablets works differently than that of desktop and laptop computers. Also, mobile hardware has come a long way to work smarter and consume less power overall.

How Android Has Matured

Laptop and desktop computers process software/applications and manage resources differently than mobile devices running the Android operating system (OS). For example, with the Windows OS, less available memory means a slower system experience. It’s why adding memory is an easy way to boost PC performance.

But the latter is designed to operate the same way no matter how full or empty the memory may be — it’s normal for an Android device to use up half or more of total available memory. In fact, having apps stored in memory often results in better battery performance.

That's because apps stored in an Android's memory are essentially paused and inactive until you choose to load (basically unpausing) the app again. This is a good thing since loading apps from memory is faster and less CPU-intensive than fully-loading from device storage. It doesn’t matter, really, if your Android memory is completely full or empty; battery power only gets used when the CPU is actively processing activities. In other words, just because an app is stored in Android’s memory doesn’t mean it’s doing anything to use power.

The Android operating system is designed to automatically remove apps from memory when more is needed in the moment, opting first for lowest-priority (ones you haven’t used as much). It’ll keep going until there is enough available memory to reassign and run whatever app you’ve just loaded. This wasn’t the case with the early versions (prior 2.2) of Android, which were prone to leaving apps actively running indefinitely. Back then, task killers were far more effective and necessary.

Mobile Hardware Has Evolved, Too

Older-generation smartphones and tablets used processors with standard-sized cores that focused on maximum power. These processors would throttle core speeds in real time to match activities — not very efficient. Many of today’s multi-core mobile processors have both improved performance and the capability of intelligently handling tasks. ARM (a manufacturer of mobile processors used in the vast majority of smartphones and tablets) utilizes a design that combines both small and big cores together, which results in far greater efficiency.

Here's an example: an 8-core ARM CPU features four little cores in one processor and four big cores in the other processor. When a user engages in an activity, the system decides the appropriate core size; small activities (e.g. sending a text message, opening a document, etc.) can be handled by small cores, while more intensive activities (e.g. recording video, mobile games, loading multiple web pages, etc.) would use big cores. This approach allows processes to run quickly without using excess power and wasting battery life. As such, today’s devices last longer, even if they’re running lots of processes at once.

Should You Use an Android Task Killer?

The general consensus is that modern Android smartphones and tablets have little need for a task killer, especially since Android’s built-in Application Manager lets you force-stop apps on demand. Also, some Android devices come with the Smart Manager app, which is a task killer.

While the Smart Manager may not be crammed with features, it shows how much total RAM is being used, lists all the background apps (with the amount of RAM and CPU power each is currently using), and offers the option to kick any/all apps out of memory. The Smart Manager also details battery usage and storage data.

Vocal opponents of task killers claim that such apps do more harm than good, which may be a bit of an exaggeration. Running a task killer is unlikely to utterly destroy your device; you just may not experience much (if any) battery savings for your efforts. 

Pros of Using Task Killers

There are a few situations where you might want to use one:

  • They can help you find ‘problem’ or ‘rogue’ apps — ones that are steadily using up processing power for no apparent reason — so you can uninstall and replace them with a better alternative.
  • Smartphones and tablets running older versions of Android OS can still benefit from task killers since the older versions aren’t as capable with process management as newer ones.
  • Task killers can help with apps that are constantly trying to connect to the internet and/or send push notifications, which drains the battery (especially if the device wakes and turns the screen on each time).

Cons of Using One

On the other hand, you might want to just skip it since:

  • Task killers use processing power to do their job, so energy savings may be marginal at best, especially if the force-stopped apps weren’t doing anything to consume power.
  • Some (essential/system) apps automatically restart after being forced to stop. Such situations prompt a back and forth cycle with the task killer, which ends up using significantly more processing power and battery life.
  • Most background services/processes don’t use a whole lot of memory when not actively doing something. Plus, many of them are running in the background for a reason (see below).
  • There are times when you want apps to run in the background, such as reminders, updates, messages, alarm clocks, and more. Using a task killer could lead to many missed appointments or events.

A Few Options for You

If you have your heart set on using a task killer, we have a couple of good suggestions for you as well as some alternative apps that can help save energy without the controversy of force-stopping tasks.

  • ES Task Manager: App developer, ES Global, combines all the task-killing features you want along with a host of other useful tools: cache cleaner, startup manager, file manager (ES File Explorer File Manager, basically), and more. The interface is smart and simple to use.
  • Clean Master: In addition to freeing up RAM with a single touch, Cheetah Mobile’s Clean Master 2017 also helps by removing residual junk files, scanning for viruses, and improving Wi-Fi security. This is the same developer that makes Android’s Smart Manager app.
  • Watchdog Task Manager: Although Watchdog Task Manager can kill background apps, its real focus is centered on monitoring CPU usage and alerting the user. Created by Zomut LLC, Watchdog lets you know when any app has gone rogue (i.e. consuming a considerable amount of power). Instead of blindly killing all apps, you can select just the out-of-control one.
  • SystemPanel 2: This app does not boost, clean, or kill any apps (developer, NextApp says so explicitly in the description). Instead, SystemPanel 2 offers an extensive look into everything going on in your device, complete with using colorful bars, charts, and plotted graphs for visual presentation. The detailed information shown for battery consumption will let you know which apps are the biggest drain.
  • JuiceDefender: Created by Latedroid, JuiceDefender has been saving battery life for years without the need to kill tasks. What this app does is manage battery-draining elements (e.g. Wi-Fi, mobile data, screen, etc.) through hibernation-like settings, schedules, and triggers — similar to yet more comprehensive than Android Marshmallow’s Doze Mode.