Memory
How to free up RAM on a Mac (what actually works)
Updated · 6 min read
Before freeing memory, check whether you need to. macOS is designed to use almost all of your RAM, keeping spare memory full of caches it can hand back instantly. What matters is whether apps have enough. Here's how to tell, and what to do when they don't.
1. Check memory pressure, not memory used
Open Activity Monitor's Memory tab and look at the Memory Pressure graph at the bottom. Green means your Mac has the memory it needs, even if "Memory Used" looks nearly full.
Yellow or red is when freeing memory helps. See what memory pressure means.
2. Quit the apps using the most
Sort the Memory tab by the Memory column. The biggest users are usually browsers, design and video apps, virtual machines, Docker and code editors. Quitting one large app frees far more than anything else you can do.
Apps you've closed the window of may still be running: look for a dot under their Dock icon and press ⌘Q to really quit them.
3. Close browser tabs
Every tab runs as its own process, and a busy web app can use hundreds of megabytes. Close tabs you don't need, and use your browser's built-in memory saving. In Chrome that's Memory Saver; see Chrome using too much memory.
4. Restart
After days of uptime, swap and leaked memory build up. A restart clears both in a minute and is often the single most effective fix. Check how much swap is in use under Swap Used in the Memory tab (what is swap?).
5. Stop apps starting at login
Apps that launch at login take memory all day. Remove the ones you don't need in System Settings › General › Login Items & Extensions.
What doesn't help: RAM cleaner apps
Apps that promise to "free RAM" mostly clear macOS's caches. The memory looks free for a moment, then macOS has to reload that data from disk, which makes things slower. The same goes for running sudo purge in Terminal.
Tip
Do you need more memory?
- If memory pressure is red during your normal work, yes: your next Mac should have more memory.
- If it only turns yellow when you have an unusual number of apps open, no: closing apps is enough.
- On current Macs memory can't be upgraded later, so choose generously when you buy.
Keep an eye on memory without opening Activity Monitor
Tempo for Mac shows memory use and pressure in its menu bar panel, lists the ten busiest apps by memory, keeps 30 days of history and can notify you when pressure stays high.