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HappyMac features:

  • Automatically suspends background processes
  • Stops your CPU from heating up
  • Preserves battery life
  • Makes your Mac happy again


Three ways to install HappyMac:

How it works

HappyMac is a status bar app for Mac with an icon showing in the status bar. The icon itself changes from happy to unhappy to sweating to mad, depending on the current load of your Mac. In the menu above, the machine is showing as sweating, as the overall CPU usage on the machine, including all available cores, is currently in between 51% and 75%.

The menu shows three categories of processes:

  • Current App Tasks: These are the processes that make up the process family of the currently active application. This includes the process that created the currently active window and all its parent processes up to the Launch process. Also included are all the child processes of the current process, their child processes, etc.

  • Background Tasks: These are tasks that use up CPU even though they run in the background. Literally hundreds of tasks normally run in the background and they only become troublesome when they run hot.

    At any point in time you can decide to suspend any background task using the context menu, as is shown above. What happens is that the given task is suspended and moved to the suspended tasks. HappyMac also remembers this decision and will make sure the process is suspended any time it is not part of the foreground task family.

  • Suspended Background Tasks: Suspended tasks are those that are currently suspended by HappyMac. You can resume a suspended task by bringing the process to the foreground, assuming it has a UI. You can also manually resume a task using the context menu.

HappyMac Logic

Once a suspended process is activated, by using Cmd+Tab for instance, all the processes in its family are resumed. The logic for suspending and resuming is currently hardwired into HappyMac.

To remove noise, active processes that use up less than 3% of CPU are not shown. Unlike the overall CPU represented by the status bar icon, a given task can use more than 100% of CPU. This is the case when a task uses more than one core of the machine. Most Macbooks have 4 cores and some even 6. It is quite uncommon for a process to use more than 100% of the CPU. Few processes use more than 2 cores.

Just like the task bar icon, each individual task gets a different emoticon for each percentage of CPU it uses. The same scale is used. A happy process uses 25% CPU or less (of one core), an unhappy 50% or less, a sweating one 75% or less, and a mad one more than 75%.

A Practical Example

Say we are developing an Android app and start up the Intellij IDE. From it, we launch the Android emulator. CPU goes up, as we can tell as it will not take long for the Macbook's fan to turn on. When we switch to another application, both the idea and qemu-system-i386 tasks keep using CPU.

Together, they use up more than two cores. Eventually, idea will slow down and not use any CPU anymore, but the second task (which is the Android emulator) keeps on using CPU, even when it is "not doing anything". With HappyMac, such processes can be automatically suspended.

Admin Tasks

Sometimes, you may want to suspend a process that does not belong to your current user account. In such a case, HappyMac will ask you to provide an admin or root password for your machine, so it can "sudo" suspend the process. The dialogue will look like this:

Critical Tasks

Some Mac tasks are part of the operating system and have a critical function. One such example is WindowServer. It is the process that draws your display and handles events. If you suspend that process, the only recovery would be to shut down your mac by pressing the power button for 5 seconds. Processes like WindowServer will not be suspended by HappyMac:

Terminating Tasks

The context menu on processes listed in HappyMac have a menu item to Google for the meaning of the task. In addition to that, it also has a Terminate menu item. We strongly recommend you do not terminate processes. HappyMac will show a warning and ask you to confirm you really want to terminate the process, rather than suspend it.


HappyMac is written in Python and uses psutil to list all processes every two seconds, compute their CPU, compute the current foreground task family and resume it, if needed. Any previously suspended process that is now running in the background will be suspended automatically as well. If the status bar menu is open, it is redrawn to show the current state.

To draw the status bar menu and the dialogs shown above, rumps is used.

The distribution, i.e., the DMG file, is created using PyInstaller.


Want to contribute? Great! Simply download this git repo and send a pull request.

What is next?

It would be great to add more refined policies for suspending processes. Policies to consider:

  • Only suspend a background process when it uses more than 35%
  • Only suspend process X when I am on battery
  • When doing a build, don't do backups
  • When I am tethered to my phone, suspend process that use the network for more than X MB per minute
  • When the CPU is below 30% for a while, it is OK to run backups

Rules of Engagement

When you actually run HappyMac, be aware you agree with the Privacy Policy and Terms & Conditions.

Furthermore, please make sure you are in compliance with your company's IT policy when using HappyMac on your work laptop.



Build HappyMac Yourself

You can build HappyMac yourself, or run "python src/" from a local repo.

However, for daily use, we suggest you visit and download the ready to install DMG of HappyMac.


A Python Mac app to suspend background processes







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