Free Up Inactive Memory On Your Mac Using The Terminal Purge Command

Memory management is a very important aspect of Mac OS. You will often find your mac running slow, after you have been using it for a few hours. This is due to memory being created and deleted.

Often Mac OS won’t free the memory for awhile, this makes it build up. If you have a mac with only 2GB/4GB of ram it can soon get full. Once it’s full the mac will go extremely slow and you will find applications crashing more often.

There is a fix for this without restarting your mac.

Using Terminal

Using the terminal to free the memory is very simple but you will have to own the developer tools. We will go over the command purge, which gets rid of all the inactive memory in your ram.

The system will show you 4 different types of memory.

  • Free memory is any memory that is not used, which can be used by applications.
  • Inactive is memory which has been used before but is no longer used.
  • Active memory is what your applications are currently using.
  • Wired memory is system memory that Mac OS is using.

To cleanup the inactive memory you can open applications -> utilities -> terminal.

Warning – Please purge use with caution as it’s not 100% safe to use.

Type in the command:
Then press enter.

This should take a few mins, there maybe a slowdown until it’s finished. Once it’s finished your mac should run a lot smoother.

Using Software

If you don’t fancy using the terminal, then you can use software. One of the best applications i’ve used is FreeMemory.


Price: Free Company: Rocky Sand Studio

FreeMemory is a free app on the mac appstore. The application is designed specifically for freeing memory.

Once you download the app from the store:

You should see the memory usage in the top right toolbar. If you click it and go to usage you should see exactly how much memory your mac is using.

If you want to free the inactive memory simply select free memory. This should take 1 min or so.

If your mac only has 2GB of ram, i would recommend upgrading to atleast 4GB. To get maximum performance. You will see a huge difference in general usage.

Before you go

After spending over 20 years working with Macs, both old and new, theres a tool I think would be useful to every Mac owner who is experiencing performance issues.

CleanMyMac is highest rated all-round cleaning app for the Mac, it can quickly diagnose and solve a whole plethora of common (but sometimes tedious to fix) issues at the click of a button. It also just happens to resolve many of the issues covered in the speed up section of this site, so Download CleanMyMac to get your Mac back up to speed today.


About the author


I've been a passionate evangelist for Apple and the Macintosh throughout my working life, my first love was a Quadra 605 working with a small creative agency in the south of Norfolk UK in the mid 1990's, I later progressed to other roles in other Macintosh dominated industries, first as a Senior graphic designer at a small printing company and then a production manager at Guardian Media Group. As the publishing and printing sector wained I moved into Internet Marketing and in 2006 co-founded blurtit.com which grew to become one the top 200 visited sites in the US (according to Quantcast), at its peak receiving over 15 million visits per month. For the last ten years I have worked as an Affiliate and Consultant to many different business and start ups, my key skill set being online marketing, on page monetisation, landing page optimisation and traffic generation, if you would like to hire me or discuss your current project please reach out to me here.

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