App Tamer Mac

The App Tamer gives you the power to decide which apps run and which ones are stopped, thereby extending your laptop’s life and letting your Mac run its best. You can choose to auto-pause, shut down or restart apps when not in use, reduce CPU load for resource hogs such as Google Chrome, Firefox and Safari, detect excess CPU usage on. Download App Tamer 2.6.1 for Mac from our software library for free. The most popular versions of the application are 2.0, 1.3 and 1.2. The size of the latest downloadable installer is 9.6 MB. This program is developed for Mac OS X 10.7 or later. The unique identifier for this program's bundle is com.stclairsoft.AppTamer.

Version 2.6.2 of App Tamer is available, fixing a couple of user interface bugs that could trip up new users. When newly installed, the size of App Tamer’s window was much smaller than it was supposed to be, making it hard to see the list of tamed processes. Compounding this was a change in version 2.6.1 that resulted in the mouse cursor not turning into a little arrow when you hovered over the edges of the window, so you couldn’t tell it’s resizable.

Another glitch, a result of changes that Apple made in Big Sur, could result in the names of processes being truncated in the process list. That’s been fixed as well.


You can find the full release notes and download links to App Tamer 2.6.2 on the App Tamer Release Page.

An experimental feature for a very specific system problem:

And now for the geeky, experimental feature: It’s come to my attention that some people are living with bugs in macOS that can result in essential background processes (like lsd and pkd) suddenly consuming tons of CPU time and bringing their Mac to a standstill. Despite chasing around to try and find the culprit, they often can’t resolve the problem without completely reinstalling the system. And apparently, App Tamer’s process throttling can’t limit the CPU usage without effectively disabling whatever function those processes are supposed to be performing.

So I’ve added a “runaway process assassin” to App Tamer. You specify which processes to watch, and if the CPU usage of any of them stays above a specified limit for a certain amount of time, App Tamer just kills the process. This certainly isn’t ideal, but works fine for system daemons that macOS will automatically relaunch whenever they’re needed. This feature is probably only useful to a few people, but because it isn’t something that’s easy to code up with an AppleScript or shell script, I figured I’d just add it. App Tamer is already collecting the CPU statistics anyway.

App tamer mac

To configure this, you have to use Terminal. Paste in these commands, hitting the Return key after each one:

Here’s what’s going on with the commands:

App Tamer Mac

  • The first command turns on the killRunawayProcesses feature.
  • The second sets runawayProcessCPULimit to 50. You can set that to whatever CPU percentage you want.
  • The third sets runawayProcessTimeLimit to 20. This is how long (in seconds) the process has to be above its limit before App Tamer kills it.
  • The fourth sets runawayProcessList to watch lsd and pkd. You can add as many processes as you want here, separated by spaces. For full-fledged applications, use the app’s bundle identifier.

App Tamer For Mac

When App Tamer kills a process, it will put up a notification to let you know. You’ll probably want to make sure you’ve allowed App Tamer to display notifications in System Preferences > Notifications.

To turn the whole thing back off, just use:

WARNING: Don’t turn this on unless you have a real need for it! You could potentially kill a service that’s necessary for your Mac to operate correctly. However, if you do need and make use of this feature, I’d appreciate hearing from you in the comments or at [email protected]

'Pure gain with no pain' - Macworld
'A Must-Have Mac Utility' -

Got Unruly Applications?

Some applications, particularly web browsers and older apps, continue running tasks or animating ads even when they're idle. That uses valuable processing (CPU) power, which leaves you with:

  • Less CPU power for the application you're using
  • Increased heat and fan noise
  • Reduced battery run-time

Tame Them with App Tamer

Find the culprits and get them under control. With App Tamer, you simply do this:

  1. Launch App Tamer and click on its icon in your menubar
  2. Click on an application that's using a lot of CPU
  3. Tell App Tamer to slow or stop the app

App Tamer will automatically slow down or pause your applications whenever you're not using them, greatly reducing their CPU use.

App Tamer even comes pre-configured to automatically reduce the CPU and battery usage of Safari, Firefox, Google Chrome, Spotlight, Time Machine, Photoshop, Illustrator, Word and many other applications.

App Tamer Does All The Work

Unlike some utilities that let you manually stop processes, App Tamer automatically handles the details for you. It slows or pauses an application when you switch away from it, then automatically restarts it when you start using it again. Just set it and forget it - App Tamer quietly saves battery and CPU power while you work (or play).

But You're in Control

You choose which apps to manage. Automatically stop them when you're not using them, or just slow them down so they don't use more than a certain amount of CPU.

App Tamer's preferences let you tune its behavior to your needs, whether you're frugally conserving battery power or feeding every last CPU cycle to Starcraft.

Road Warriors Take Note!

Recovering even a small percentage of your CPU time can translate into significant battery savings. Stopping an application that's consuming 5% of your CPU can translate into 20 or 30 minutes of additional battery runtime.

Detect CPU Hogs

Sometimes an application or macOS system process suddenly starts using large amounts of CPU time. There may be new work to do after you've added new pictures to Photos, for example, or it could be due to a bug somewhere in an app or in macOS itself.

App Tamer detects excessive CPU usage like this and alerts you, letting you decide whether to take control or let the process continue.

What About App Nap?

Apple knows a good thing when they see it. macOS has App Nap, a feature that 's similar to App Tamer. But to activate it you have to hide or completely cover an application's windows, making it not-so-automatic. And App Nap doesn't work at all with behind-the-scenes processes like Spotlight and Time Machine. App Tamer does!

Also accelerate your Time Machine backups!

Increase the speed of your Time Machine backups with the simple click of a checkbox in your App Tamer preferences. Click here for details and caveats

“App Tamer is a fantastic Mac utility, which literally tames background apps and processes, appreciably reducing their CPU usage, and thereby substantially speeding up a Mac, its user’s foreground task and his/her productivity. App Tamer is a must-have on every Mac!”

– Evan Katz, Managing Director, Crawford Ventures, Inc., hedge fund expert and former Contributing Editor of Personal Computing magazine

Try App Tamer Free for 15 Days
Try it for FREE for 15 days

Download Version 2.6.2
For macOS 10.9 - 11.3

Older Version 1.3.2
For macOS 10.5 - 10.7

Buy App Tamer Now
Single-user license: $14.95/each
2+ licenses: $12.45/each
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About App Tamer
What's New
User Manual
Reviews and Comments
What a beautifully simple yet revolutionary App! But don't tell Apple that I can put off upgrading my Macbooks for another year ;)
It's 'just working'. Thank you so much. Love the product. Love the support.
- Gregory Morse
A) the user interface is completely intuitive, B) it seems to work perfectly and instantaneously, and C) I did independent confirmation with my usual tool (top from the command line) and astonishingly, Safari was sitting there firmly fixed at 0 %CPU. That is awesome!!! I am absolutely going to be telling everyone I know to go buy this immediately!
System Requirements
macOS 10.9 through 11.3