This is a very common problem among the macOS users, and almost everybody one in a life time will face this error. Depending on the work you do you may see it. For example, if you are doing something like office paper you may not see this error much. On the other hand, if you are messing with heavy software and apps you will see the popup “Your system has run out of application memory” more frequently. I must mention that it is not limited to a specific version of macOS and can happen on all versions including macOS Mojave and macOS Catalina 10.15.
Why it happens more frequently on mac?
To answer the question first you need to have some understanding of the ‘memory’ on a mac hardware. Basically, the memory used on mac system is divided into three parts, and these are Physical memory also known as RAM, Cached files and SWAP.
- Physical Memory:
It is one of the most important components of all computers and smartphones. Therefore, a physical memory is extremely fast component that temporarily stores all the data before it saves on you hard drive. For example, imagine you are doing some on Adobe Illustrator CC or Adobe Premier Pro CC, and all the editing you do will be first stored on RAM before being saved to SSD or HDD.
- Cached files Memory and SWAP:
Consider you are running some heavy stuff like Adobe Premier Pro CC or Adobe Illustrator CC I mentioned before. The editing you do will be partial stored on memory (RAM) temporally, and then parts it will move to Cached files and SWAP memory.
Now imaging if you do heavy stuffs consistently together with a low space on your hard drive. The first thing will happen is the physical memory will be used to create additional space, then SWAP will be used to make some space. Once the physical memory, swap together with the hard drive you use reach its limit then the error “Your system has run out of application memory” will appear warning you.
What are the solutions ?
The quick answer is ‘create some free space’. But how you can make a free space and increase the space capacity is what I am going show you step by step.
Essential to read: Fix Application is damaged, and can’t be used to install macOS
Steps to Fix Your System Has Run Out of Application Memory:
1. Make free space on your mac storage
It is the one of most essential ways you can make some free storage on you hard drive. To do so, click on Apple icon  on the right upper corner, then “about this mac” and choose “storage”. This will show which type of data has occupied your drive.
Now click “manage” and choose “Store in iCloud”. This will allow you to choose what category (Desktop and Documents, Photos and Messages) you want to upload in iCloud from the list. But it is not a waste to select all of them and upload them in iCloud to make additional space on your hard drive.
- Delete iTunes Library Backups:
iTunes Library Backups can occupy a huge of amount of the space on your hard drive. Specially if you allow iTunes to frequently backup data.
Therefore, it is important to delete the unwanted and old files to make some free space on your mac.
To do so, open the “Finder window”, go to “Go to Folder” and type (~/Library/Application Support/MobileSync/Backup/) and delete the unwanted files.To delete the iTunes library backups type on the “Go to Folder” (“~/Music/iTunes/Previous iTunes Libraries) and delete out dated and unwanted data.
- Optimize Mac Storage
This feature is available on macOS Sierra and later and if you use an older version then macOS Sierra you may not see this option.
Basically, this will allow the macOS to automatically store content in the cloud whenever additional storage space is required. This includes files, photos, movies, email attachments, and other content.
To optimize your mac storage:
- Go to apple mini bar and click on 
- choose “About this mac”
- Click “Manage”
- Here you’re going to see couple of recommendations for optimizing mac storage across several categories.
- Empty Trash Automatically
This will deletes the unwanted and trashed files that have been in the Trash for more than 30 days.
- Reduce Clutter
If you stored large amount of data on your hard drive like movies, document and apps, Reduce Clutter will help to find them and remove them from your hard drive to make an extra amount of space.
Reset NVRAM and PRAM
In macOS the NVRAM (Non-volatile RAM) and PRAM (parameter RAM) are small amounts of RAM that store certain settings. Therefore, the settings that will be stored in NVRAM include sound volume, display resolution, startup-disk selection, time zone, and recent kernel panic information. Whereas, the settings stored in NVRAM depend on your Mac and the devices that you’re using with your Mac.
How to Reset NVRAM and PRAM
- Turn off your mac
- Restart your mac
- While it restarts hold down together the [Option key, Command, P, and R]
- Release the keys after apple logo appears or you hear startup sound
Remember that turning off your mac does not clear PRAM and NVRAM, you need to hold the [Option key, Command, P, and R] all together.
Using Activity Monitor
Activity Monitor displays a variety of resources that your mac uses in real-time. These include CPU, Physical Memory, Energy, Disk Activity and Network and how they affect your Mac’s activity, performance and memory usage.
To get into activity monitor go to Applications > Utilities or simple press CMD + Space bar to open spotlight, then search for Activity monitor. Now check for apps and programs that uses the most of memory resources and double-click on it and select “Quit” to close the program. This will make some free space on the Physical Memory.
Remember you can do the same process for the other parameter such CPU, Energy, Disk Activity and Network.
Make Disk Space with Third Party Apps
There are several third party you can use to make free space on your mac. Since I have used Clean My Mac X and it has been pretty convenient for me, I recommend you use this app to free up the memory and make free space on your hard drive. If you can not effort Clean My Mac X you use some of its alternatives include below.
Clean My Mac X Alternatives:
- Clean Me
- Stellar SpeedUp Mac
Additional Steps to Free up Storage Space Manually
You can also delete file manually to make free space on your mac.
- Delete Music, films, and media can be handy and give you some space flexibility
- Move files to an external storage device. learn here to use external NTFS drive on mac.
- Delete unwanted mails
- Uninstall unneeded apps and programs
- Delete other files that you no longer need e.g. images
- Remove downloaded apps and files from download folder
Guys, In order to fix your system has run out of application memory you need free up the physical memory and make some space on your internal hard drive. Therefore, to solve the error and free up some storage you need to read all the essential step i have included in this piece of article.