How to Check Memory Usage on Mac

September 11, 2026

See how much RAM your Mac is using, which apps take the most, and whether memory pressure is why it feels slow, using the built-in Activity Monitor.

When a Mac slows down, memory is a common cause. Activity Monitor, included with macOS, shows what is using it and whether the Mac is under pressure.

Open Activity Monitor

Press Cmd + Space, type Activity Monitor, and press Return. It is also in Applications, Utilities.

Click the Memory tab

Click Memory at the top of the window. The list shows every running process with the amount of memory each one holds.

Read the Memory Pressure graph

Look at the graph at the bottom of the window. Green means the Mac has enough memory. Yellow means it is compressing memory to keep up. Red means it has run out and is leaning on swap space on the disk, which is when everything feels slow. The numbers next to the graph show Physical Memory (installed RAM), Memory Used, Cached Files, and Swap Used. The pressure color, not the Memory Used figure, is the signal that matters; macOS deliberately keeps RAM full of cached files it can drop at any time.

Sort by the Memory column

Click the Memory column header so the largest users sit at the top. Browsers with many tabs, virtual machines, and video or photo editors are typical top entries. A high number for one app is not a problem on its own if the graph is green.

Quit the heavy apps you are not using

The cleanest way is to switch to the app and press Cmd + Q. To do it from Activity Monitor, select the process, click the Stop button in the toolbar (an X inside an octagon), and click Quit. Choose Force Quit only if the app is not responding, since unsaved work in it is lost. Leave processes you do not recognize alone; many belong to macOS and restart on their own.

If you want to know how much RAM the Mac has. Choose Apple menu, About This Mac. The Memory line shows the total. RAM in Apple silicon Macs is part of the chip and cannot be upgraded later.

If Swap Used is not zero. Some swap is normal and harmless. Swap in the gigabytes alongside a yellow or red graph for most of the day means the Mac needs fewer apps open at once, or more RAM in its next replacement.