Mac Memory Pressure — Free Up RAM and Stop App Freezing

Overview #

If your Mac starts out fast but slows to a crawl after opening several apps — or if you see spinning beachballs and “Your system has run out of application memory” warnings — it’s a sign that memory pressure is building.

This doesn’t always mean you need new hardware. Often, apps are holding onto memory, Spotlight or Photos are indexing, or the system cache simply needs a refresh.

Let’s fix it together by checking where your RAM is going, reducing pressure, and restoring smooth performance.

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Terms & Definitions #

Term	Definition
Memory Pressure	A macOS indicator showing how efficiently the system manages RAM (green = healthy, yellow = strained, red = overloaded).
Swap Memory	Disk space macOS uses when physical RAM runs out — too much swapping slows the system dramatically.
App Memory	RAM directly used by open apps.
Cached Files	Recently used data stored in memory to speed reopening; can safely be cleared when needed.
Compressed Memory	macOS compresses inactive data in RAM to free space dynamically — high compression means RAM is tight.

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Steps #

1. Check Memory Pressure #

Let’s see if memory is indeed being maxed out.

Steps:

1. Open Activity Monitor (Finder → Applications → Utilities).
2. Select the Memory tab.
3. Look at the Memory Pressure graph at the bottom:
   • 🟢 Green = Healthy
   • 🟡 Yellow = Some strain
   • 🔴 Red = Severe shortage

Terminal Command:

vm_stat 5

Watch the “Pages free” and “Pages active” numbers. If free pages steadily decline while swap grows, memory is tight.

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2. Identify Memory-Hungry Apps #

Sometimes, one or two apps are the entire problem.

Steps:

1. In Activity Monitor → Memory, click Memory column to sort.
2. Note any apps consistently consuming over 1–2 GB.
3. Quit those apps and see if the pressure graph drops.

Terminal Command:

ps -A -o pid,rss,comm | sort -nr -k2 | head -10

“rss” shows resident memory size (actual RAM use).

Common culprits: Chrome Helper, Electron apps (Slack, VS Code), Photos, and Safari tabs.

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3. Close Browser Tabs and Background Apps #

Browsers and creative apps hold onto memory long after you close windows.

Quick fixes:

• Use Safari’s Tab Groups or Chrome’s Memory Saver.
• Quit unused background apps (menu bar icons → Quit).
• Turn off Adobe AutoSync and Creative Cloud background agents.

Terminal Command (List Background Processes):

ps aux | grep -E "Dropbox|OneDrive|Creative|Google"

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4. Clear System and App Caches #

Old cached data can slowly fill memory and storage.

Steps:

1. In Finder, press Shift + Command + G.
2. Go to: ~/Library/Caches /Library/Caches
3. Delete folders of apps you no longer use.
4. Empty Trash and restart.

Terminal Command:

sudo rm -rf ~/Library/Caches/* /Library/Caches/*

Use with care — this removes all temporary caches, forcing a rebuild.

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5. Reduce Background Indexing #

If Spotlight or Photos is indexing, it can consume several GB of RAM temporarily.

Spotlight Commands:

sudo mdutil -a -i off
sudo mdutil -E /
sudo mdutil -a -i on

Photos Library Fix:

• Open Photos → Settings → General → Pause Library Repair or Sync.

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6. Manage Login Items #

Apps that start automatically can slowly fill up RAM even when idle.

Steps:

1. Open System Settings → General → Login Items.
2. Review and disable anything unnecessary (cloud apps, messengers, etc.).

Terminal Command (List Login Items):

osascript -e 'tell application "System Events" to get the name of every login item'

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7. Reset Swap and Purge Inactive Memory #

macOS dynamically manages swap space, but sometimes manual flushing helps.

Terminal Commands:

sudo purge
sudo rm /private/var/vm/swapfile*

Then restart your Mac.

purge clears inactive memory caches, while deleting swapfiles forces a fresh allocation.

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8. Disable Visual Effects #

Reducing graphical effects can lighten memory load, especially on older Macs.

Steps:

1. Open System Settings → Accessibility → Display.
2. Enable:
   • Reduce Motion
   • Reduce Transparency

Optional Command:

defaults write com.apple.universalaccess reduceTransparency -bool true

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9. Add or Optimize Virtual Memory #

If your Mac still runs out of RAM frequently, consider adjusting swap behavior or upgrading storage to SSD (if not already).

To check current swap usage:

sysctl vm.swapusage

If “used” exceeds 3–4 GB regularly, you’re running out of real memory — physical RAM or reducing background load is the solution.

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Conclusion #

You’ve just reduced memory pressure by closing heavy apps, clearing caches, and controlling background indexing.
Your Mac should now feel smoother, with fewer freezes and faster app switching.

If issues persist:

• Check Activity Monitor → Memory regularly to spot patterns.
• Avoid leaving browsers or creative apps open for days.
• If you have 8 GB RAM or less, consider upgrading to 16 GB or switching to lighter apps (like Safari instead of Chrome).

These small habits can keep your Mac responsive for years.