When an app on your Mac becomes unresponsive, check Activity Monitor’s Memory tab to see whether macOS is under memory strain. Watch the Memory Pressure graph, then compare it with the app’s memory use. A yellow or red graph that persists while the Mac is slow points to system memory pressure; a green graph suggests you should investigate other causes too.

Open Activity Monitor and check Memory Pressure

Open Activity Monitor from Applications > Utilities, or find it with Spotlight. Select the Memory tab. At the bottom of the window, note the Memory Pressure graph, Memory Used, Swap Used, and the breakdown that includes App Memory, Wired Memory, Compressed, and Cached Files. Apple says the graph reflects how efficiently memory is serving processing needs, based on factors including free memory, swap rate, wired memory, and cached files. Apple’s Activity Monitor guide

Read the graph before judging one number

Use the graph’s color as the first signal: green means memory is being used efficiently; yellow indicates the Mac might eventually need more RAM; red indicates it needs more RAM, according to Apple. If the graph is yellow or red—or shows spikes—Apple recommends checking whether an app is using memory and quitting it if you no longer need it. Apple’s guidance on checking memory pressure

Look for a pattern while the slowdown is happening. A brief color change or a large Memory Used value by itself does not establish that memory caused the freeze. macOS uses memory for caching and can compress inactive apps’ memory to make more available. Cached Files can be reclaimed when needed, so a large cache is not automatically a problem. Swap Used shows space used on the startup disk to move data to and from RAM; consider it alongside the graph and the symptoms rather than treating it as a standalone diagnosis. Apple explains these Memory tab measures

Check whether the unresponsive app is using memory

With the Memory tab open, find the affected app in the process list and examine its memory use. Compare what you see with the graph and with other apps running at the same time. If the app’s use is high while pressure stays yellow or red, and the Mac is sluggish across several apps, that supports the possibility that overall memory demand is contributing. This is a practical interpretation of Activity Monitor’s indicators, not proof that the app is faulty or the only cause.

If pressure remains green while only one app is stuck, memory pressure is less evident as the explanation. Try the app’s normal Quit command first if it responds; otherwise save what you can elsewhere and force quit it. Force quitting can discard unsaved changes, so use it only when normal quitting fails. Activity Monitor shows resource use; it does not identify every possible reason an app may stop responding.

Relieve pressure and decide what to do next

If the Mac is still responsive, quit apps and browser tabs you do not need, especially processes that appear to use substantial memory. Keep the Memory tab open and watch whether pressure settles. If a specific app repeatedly coincides with yellow or red pressure, update it and check with its developer if the problem continues. Apple notes that compatible software, updates, problematic files, peripherals, or third-party plug-ins can also matter when an app freezes, so a green graph should prompt broader troubleshooting rather than repeated memory cleanup. Apple’s troubleshooting steps for unresponsive Mac apps

If you cannot quit the app normally, press Option-Command-Esc, select it in the Force Quit window, and click Force Quit. If that fails, restart from the Apple menu. A forced quit or shutdown can lose unsaved work. Apple’s force-quit instructions

One check cannot tell you whether a Mac’s RAM is upgradeable. Apple says to hold Option while choosing Apple menu > System Information, then look under Hardware > Memory; an Upgradeable Memory section appears only on models where that option is available. Treat this as a model-specific check, not an automatic remedy for a single app freeze. Apple’s RAM guidance

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