SpotlessHow to free up memory (RAM) on a Mac
A Mac that uses all its RAM is working normally. macOS fills spare memory with cached files and gives it back the moment an app asks. The number to watch is Memory Pressure in Activity Monitor. If the graph stays green, you have nothing to fix. If it turns yellow or red, quit the apps at the top of the Memory column.
Read memory the way macOS reports it
Open Activity Monitor (Applications, Utilities) and click the Memory tab. Ignore the big "Memory Used" figure at first. It includes memory that macOS can reclaim instantly. Four numbers tell the real story.
- Memory Pressure is the graph at the bottom. Green means plenty of room. Yellow means macOS is compressing memory to cope. Red means it is struggling and your Mac will feel slow.
- Compressed is memory squeezed to save room. It costs a little processor time and is a normal part of macOS.
- Swap Used is memory written out to your SSD. A few hundred megabytes is routine. Several gigabytes, growing during a normal workday, means the Mac has less RAM than your work needs.
- Cached Files is the spare memory macOS uses to keep recent files ready. It is not wasted, and it counts as available.
For a quick check from Terminal, memory_pressure prints the same verdict and the percentage of memory that is free.
What frees memory in practice
- Sort by memory and quit the top few. In Activity Monitor, click the Memory column header. A browser with 40 tabs, a video editor left open overnight, or an Electron app like Slack or Teams often holds several gigabytes each. Choose Quit before Force Quit, so the app can save its work.
- Close or suspend tabs. Safari and Chrome both free memory from tabs you have not used for a while. In Chrome, turn on Memory Saver under Settings, Performance. Closing a tab you will not read again frees more than any tool can.
- Trim login items. Apps that start at login keep a share of memory all day. Open System Settings, General, Login Items and remove what you do not use.
- Restart after weeks of uptime. Some apps leak memory slowly, and a restart returns all of it. A Mac used daily benefits from a restart every week or two.
- Check for one runaway process. A single process using far more than its share, often after an app update, is a bug. Quitting it fixes the problem.
Why memory cleaner apps do not help
Most "memory cleaner" tools work by asking macOS to drop its cached files, which is what the Terminal command sudo purge does. The tool then reports a large number of gigabytes freed. That memory refills with the same cached files within minutes, and in the meantime your Mac reads those files from the SSD again, which is slower than reading them from memory. The graph looks better for a moment and the Mac gets no faster.
The exception is a real shortage of RAM, and no cleaner can create RAM. In that case the fix is to run fewer things at once, or to buy a Mac with more memory.
Do you need more RAM?
Apple silicon Macs cannot have memory added later, because it is part of the chip package. Check these signs before you decide your next Mac needs more.
- Memory Pressure sits in yellow or red for most of a normal workday.
- Swap Used climbs past several gigabytes and stays there.
- You use the same few heavy tools every day, such as Xcode with simulators, Docker, large Photoshop files or several virtual machines.
If none of those apply, a restart and a few quit apps are the fix.
What Spotless does about memory
Spotless has a Memory page that lists the apps using the most memory right now, with the memory pressure verdict above them and a Quit button on each row. It does not have a "Free RAM" button, on purpose, because the button would only run purge and make your next few minutes slower. The menu bar item turns orange then red as memory fills, so you see the problem when it starts. Read about the Memory page, or the menu bar monitor.
Keep going
- How a Spotless clean works: Scan, look, choose, review, Trash.
- Pricing: Every feature for $9, once.