Mac memory pressure: why high RAM use is often fine

Why is my Mac using almost all of its RAM?

Because macOS puts its memory to work. Apple says free memory doesn’t necessarily mean better performance: macOS performs best when it uses and manages all of its memory efficiently. It keeps recently used files in memory that would otherwise sit empty, and it compresses memory held by inactive apps to make room for active ones.

So a Mac with 21.40 GB of its 24 GB in use can be working perfectly well. The number to check is memory pressure.

How do I check memory pressure?

1. Open Activity Monitor. It’s in Applications > Utilities, or search for it with Spotlight.
2. Click Memory at the top of the window.
3. Look at the Memory Pressure graph at the bottom:
   • Green: your Mac is using all of its RAM efficiently.
   • Yellow: your Mac might eventually need more RAM.
   • Red: your Mac needs more RAM.

Apple says the graph is based on free memory, swap rate, wired memory and file-cached memory. It already takes into account what macOS can make room for, which is why it’s a better guide than the amount in use.

What do Memory Used, Cached Files, Compressed and Swap mean?

The numbers beside the graph explain where the memory is. Here they are with the values from the picture above:

Cached Files is shown apart from Memory Used. It’s memory macOS lends to files you may open again, and it gets overwritten when something else needs the room. A little swap is normal too. Swap that keeps growing while memory pressure is yellow or red means your Mac is short of memory for what’s open.

What should I do if memory pressure is yellow or red?

Yellow or red means your Mac is short of memory for what’s open. Compressed memory and swap grow as macOS makes room.

1. In Activity Monitor’s Memory tab, click the Memory column heading to sort the list, largest first.
2. Quit the apps you aren’t using, from their own menus. Save your work first.
3. If an app isn’t responding, select it, click the Stop button at the top of the window, then choose Quit. Choose Force Quit only if Quit doesn’t work, because unsaved work in that app is lost.
4. Close browser tabs you’re done with.
5. Watch the graph for a minute. If it turns green again, that was enough.

If memory pressure stays yellow or red with only the apps you need, your Mac needs more memory for that work. Is 8 GB or 16 GB of RAM enough for your Mac? helps you choose how much for your next Mac.

Questions people also ask

Is it bad that my Mac’s memory is almost full?

No, as long as memory pressure stays green. macOS uses spare memory on purpose, for apps and for files you may need again.

Does freeing up RAM make a Mac faster?

Not while memory pressure is green. Apple says free memory doesn’t necessarily mean better performance.

What is wired memory on a Mac?

Wired Memory is memory macOS needs to operate. It can’t be cached or moved out of RAM, so other apps can’t use it.