Do Mac memory cleaners work?

Briefly. Clearing the file cache makes the free number jump, but macOS fills it again because cached files open faster. Quitting apps you don’t use is what lowers memory pressure.

What is memory pressure?

How hard macOS is working to find memory for apps. Normal means there’s room; Elevated and Critical mean it’s compressing memory and writing it to disk as swap, which is when a Mac slows down.

Why does Free Up Memory ask for my password?

Clearing macOS’s file cache needs an administrator’s permission, so macOS asks for your password before it runs.

Is swap bad for my Mac?

A little is normal. Swap that keeps growing while pressure is high means apps want more memory than the Mac has, and quitting some is the fix.

Peekaboo · Memory

See what’s using your Mac’s memory, and free it the honest way

Most “RAM cleaners” show a scary number and a big button. Used memory isn’t the problem; memory pressure is. Peekaboo shows the pressure, the apps behind it, and the step that actually helps: quitting what you aren’t using.

Download free trial14 days free · macOS 14+ · Updated November 7, 2026

What it does

Pressure, not just a number: Memory pressure as Normal, Elevated or Critical, swap in use, and how memory splits into apps, wired, compressed, cached files and free.
Apps by memory, with Quit: Every open app and how much it holds, its helper processes counted toward it, with Quit right there. An app can still ask to save your work.
Free Up Memory, explained: Clears the memory macOS holds as file cache, after asking for your password. The page says plainly that quitting unused apps frees more.
From the menu bar too: The menu bar menu shows memory used and the pressure, with Free Up Memory and Show What’s Using Memory. Mac Health sends you here when memory pressure costs points.

How to use it

1Open Memory.⇧⌘P
2Check the pressure, then look at which apps hold the most.
3Quit what you aren’t using, or use Free Up Memory if pressure stays high.

When another app fits better

If pressure is Normal, your Mac doesn’t need its memory freed: macOS hands cached memory to apps the moment they ask. For every process, its threads and energy use, Activity Monitor is the tool, and [iStat Menus](/alternatives/istat-menus/) or [Stats](/alternatives/stats/) (free) graph memory over time.

Questions

Do Mac memory cleaners work?: Briefly. Clearing the file cache makes the free number jump, but macOS fills it again because cached files open faster. Quitting apps you don’t use is what lowers memory pressure.
What is memory pressure?: How hard macOS is working to find memory for apps. Normal means there’s room; Elevated and Critical mean it’s compressing memory and writing it to disk as swap, which is when a Mac slows down.
Why does Free Up Memory ask for my password?: Clearing macOS’s file cache needs an administrator’s permission, so macOS asks for your password before it runs.
Is swap bad for my Mac?: A little is normal. Swap that keeps growing while pressure is high means apps want more memory than the Mac has, and quitting some is the fix.