Summary: System runs out of application memory on Mac is a problem that you may get hit with. This post will explain what application memory is and why system runs out of memory. And six workable methods are offered to help you solve this out-of-memory problem on your Mac.

When using Mac, you may get an error message saying that the system has run out of application memory and asking you to force quit apps that you are not using. You don't know why this happens because you just open a few programs. Or, after upgrading to macOS Catalina, Mojave or High Sierra and more, you find that the computer runs more slowly than before and keep saying that it has run out of application memory.

This out-of-memory problem on Mac may make you panic. In this post, you can learn what application memory is and various methods to fix the problem. Read on.

What does system has run out of application memory mean?

When your Mac says system has run out of application memory, it means that your computer doesn't have enough memory required by applications to run. Two possible reasons account for the problem. 

1. Your boot disk has little free space for running apps. When running an app on Mac, if all physical RAM are used, macOS will create swap files, which takes up disk space. So it may take more memory and If your hard drive is full and there is no room for the swap files, the system will report that it has run out of application memory. Or you have lots of free disk space, while the currently running apps need such a large amount of virtual memory address space that macOS fails to provide. 

2. Memory leak also contributes to the problem. When a program is using more and more space over time as it runs and fails to release memory, you can recognize it as a memory leak. It will keep asking your Mac for more space but didn't give them back, which makes the system run out of application memory. And thus, the error message pops up. 

Your system has run out of application memory, how to fix? 

If your Mac is running painfully slowly or you often get the dreaded error message, it is possible that you have used your Mac's memory to the max. Here are six methods that can help you check and free up your Mac's memory. Go through the following article to find the one that works for you.


1. Force quit unused applications 

When the Force Quit Applications window opens, you can select the unused apps and click Force Quit to quit the processes that hog memory. Or you can force quit more than one applications in Activity Monitor. 

Step 1Open Finder in the Mac dock

Step 2Find Activity Monitor, and then double-click the icon

Step 3Under the Memory pane, select the program that you want to force quit, click the Force Quit or Quit button

Force Quit App Activity Monitor

Tip: how to restore paused application 

If the system has run out of application memory when you are using Adobe Premiere or Final Cut Pro, the system may pause Premier Pro, Final Cut Pro, which make you unable to save the project you are working on with this application. Here is a tip to restore the paused application after you have quit all the other applications and get memory space. 

You can use the Terminal and enter the ps command. All the running process will be present with its PID(Process ID). Get the process ID of the paused application.  

In the Terminal window, enter the command: kill-CONT process ID. For example, if the process ID of the paused app is 2650, enter: kill-CONT 2650 and hit the Enter key, which will tell the paused app to restore and run.

2. Check memory usage in Activity Monitor 

When your Mac slows down or reports that it has run out of application memory, you can check Activity Monitor to see what is using memory. It can show you how much memory is used and help to identify which app is using more than its fair share of space. To check Activity Monitor, simply click the Application folder > Utilities Activity Monitor Memory

Under Memory, you can see the memory pressure box, in which you can see details about memory usage. There is a graph giving an overview of your system's memory pressure. If the graph is green, it means that you have enough disk space, if yellow or red, you are short of memory. Check memory usage of your computer can help you figure out which apps are using more memory. Then you can quit and restart them.

Check Memory usage


3. Restart your Mac 

Restarting your Mac is the easiest way to free up space on your Mac. If you didn't regularly reboot your Mac, the computer will store many data like cookies data, form data, caches, etc., which will take up more and more memory. When restarting the computer, it will empty the RAM and caches so that your Mac can run more smoothly. 

However, restarting computer is not convenient when you don't want to be interrupted or your Mac hangs. Also, after your Mac restarts, avoid opening many apps and web pages at one time, especially space-hogging apps such as MS Office, 3D CAD, Adobe and web pages with ads, videos, flash, plug-ins.

4. Clean disk space on your Mac 

The methods mentioned above are temporary solutions. To keep away from the out-of-memory alert on your Mac, enough free disk space for running application is necessary. Generally, you need to find out the unwanted files for free space one-by-one. That's time-consuming. If you want to save much more time, you can choose FonePaw MacMaster to help you clean up your Mac's disk space only in several simple clicks. 

FonePaw MacMaster is designed for Mac memory optimization and disk cleanup. It can scan out system files that are safe to delete in your Mac and allows you to select and delete unwanted files & duplicate files. You can also uninstall unneeded apps and close login items and more. More importantly, with FonePaw MacMaster, you can clean up various types of files by one-click. This is easier and convenient. Keep reading to learn how to do that.

 Free Download

Step 1Launch FonePaw MacMaster on your Mac

Step 2Select one of the options in the left-side menu, such as System Junk, Duplicate Files or Uninstaller.

Step 3Click Scan to find out the files.

Step 4Choose the unwanted files and click Clean to remove them.

Clean Disk Space On Mac

5. Organize your desktop 

Some of you may prefer to save files, images or others on your desktop. However, this will also slow your Mac. Every desktop icon on macOS is considered as an active window. More desktop icons, more used memory and your Mac are easier to run out of application memory. So, organizing your desktop and removing some unneeded files help to clean up your Mac and reduce the "run out of application memory" alert. 

To organize your desktop, you can create a new folder on your desktop, then drag the documents, images, music or other files into the folder.

6. Limit the memory used by Finder 

When opening Finder, your Mac's file manager, you will see the default option All My Files. It is set to search all your files when you browse files and it also stores the path of all your files in RAM, which would consume a huge amount of memory, leaving fewer memory for applications to use. 

To reduce the memory used by Finder, you should avoid loading all your files when the Finder opens. To do this, you need to:  

Step 1Click Finder on the top-left of the screen, select Preferences...

Limit Memory Used By Finder Setting

Step 2Under General, click the drop-down list to select a folder. (Don’t select All my files or Recents as the location)

Reduce Memory Used By Finder

Step 3Hold down the Control key, then right-click the Finder icon in Mac dock. Select Relaunch.

With these helpful methods, I think you've saved space for your Mac. If you have any questions, welcome to share with us in the comments.