Read memory the right way
A full memory bar is normal on a Mac. Learn the one reading that tells you when it is not.
- Time
- 3 minutes
- Steps
- 5
What you need
- l/Activity open, with Monitor on.
Steps
Step 1. Open Memory and read the sentence
Press ⌘3. The stage sums the situation up in a line such as "Under half of 48 GB is in use; pressure is normal."
MemoryPhysical memory, compression, and the pressure on your Mac.Search or jump to…⌘KPauseRecordLive10:42:18Under half of 48 GB is in use; pressure is normal.Physical memory is shared by the CPU, GPU and Neural Engine. macOS can reclaim file cache when memory is needed.Pressure NormalSwap used 0 bytes · memory stored on disk21.4GBestimated used of 48 GBMemory used = app + wired + compressed012 GB24 GB36 GB48 GBApp / internal14.2 GB29.6%Wired4.1 GB8.5%Compressed3.1 GB6.5%File / purgeable cache12.8 GB26.7%Free13.8 GB28.8%Memory pressureNormalElevatedCriticalreported by macOS · every 2sNormal in every measured pressure sample · last 10 minShare in useof 48 GB44.6%estimated non-cache useMemory over timeEstimated memory used as a share of 48 GB physical memoryAll1 min5 min15 min100%50%0%10:32:1810:37:1810:42:18Memory used300 / 300 samplesClick or drag across the chart to inspect a sample.Inside your unified memoryKernel VM categories · estimates may differ from Activity MonitorApp / internal14.2 GB29.6%Wired4.1 GB8.5%Compressed3.1 GB6.5%Memory used · app + wired + compressed21.4 GB44.6%File / purgeable cache12.8 GB26.7%Free pages13.8 GB28.8%Physical memory48 GBPercentages are shares of 48 GB physical memory · Sample 10:42:18Largest memory workloadsFootprint where available, resident memory otherwiseSample 10:42:18Footprint or resident memoryL6.8 GBLumen Edit6 processesH5.6 GBHarbor9 processesK4.2 GBKite Browser23 processesF3.1 GBForge IDE14 processes2.4 GBkernel_task1 processExplore all processes* Marks a partial total when some measurements are unavailable.† Marks a total that includes resident-memory fallback.Step 01 Step 2. Look at memory pressure first
MEMORY PRESSURE is a single strip with three zones: Normal, Elevated and Critical. A mark sits under the zone macOS reports right now.
Normal means macOS is meeting every request for memory. This matters far more than how much memory is free. A Mac with almost no free memory and Normal pressure is working exactly as designed.
MemoryPhysical memory, compression, and the pressure on your Mac.Search or jump to…⌘KPauseRecordLive10:42:18Under half of 48 GB is in use; pressure is normal.Physical memory is shared by the CPU, GPU and Neural Engine. macOS can reclaim file cache when memory is needed.Pressure NormalSwap used 0 bytes · memory stored on disk21.4GBestimated used of 48 GBMemory used = app + wired + compressed012 GB24 GB36 GB48 GBApp / internal14.2 GB29.6%Wired4.1 GB8.5%Compressed3.1 GB6.5%File / purgeable cache12.8 GB26.7%Free13.8 GB28.8%Memory pressureNormalElevatedCriticalreported by macOS · every 2sNormal in every measured pressure sample · last 10 minShare in useof 48 GB44.6%estimated non-cache useMemory over timeEstimated memory used as a share of 48 GB physical memoryAll1 min5 min15 min100%50%0%10:32:1810:37:1810:42:18Memory used300 / 300 samplesClick or drag across the chart to inspect a sample.Inside your unified memoryKernel VM categories · estimates may differ from Activity MonitorApp / internal14.2 GB29.6%Wired4.1 GB8.5%Compressed3.1 GB6.5%Memory used · app + wired + compressed21.4 GB44.6%File / purgeable cache12.8 GB26.7%Free pages13.8 GB28.8%Physical memory48 GBPercentages are shares of 48 GB physical memory · Sample 10:42:18Largest memory workloadsFootprint where available, resident memory otherwiseSample 10:42:18Footprint or resident memoryL6.8 GBLumen Edit6 processesH5.6 GBHarbor9 processesK4.2 GBKite Browser23 processesF3.1 GBForge IDE14 processes2.4 GBkernel_task1 processExplore all processes* Marks a partial total when some measurements are unavailable.† Marks a total that includes resident-memory fallback.Step 02 Step 3. See what counts as used
The tall bar in the middle shows all of your memory. A bracket over its left part is labelled Memory used = app + wired + compressed. Only that part is really in use.
The grey part beside it is file cache. macOS keeps recently used files there to be quick, and hands the space back the moment an app needs it. The empty end is free.
MemoryPhysical memory, compression, and the pressure on your Mac.Search or jump to…⌘KPauseRecordLive10:42:18Under half of 48 GB is in use; pressure is normal.Physical memory is shared by the CPU, GPU and Neural Engine. macOS can reclaim file cache when memory is needed.Pressure NormalSwap used 0 bytes · memory stored on disk21.4GBestimated used of 48 GBMemory used = app + wired + compressed012 GB24 GB36 GB48 GBApp / internal14.2 GB29.6%Wired4.1 GB8.5%Compressed3.1 GB6.5%File / purgeable cache12.8 GB26.7%Free13.8 GB28.8%Memory pressureNormalElevatedCriticalreported by macOS · every 2sNormal in every measured pressure sample · last 10 minShare in useof 48 GB44.6%estimated non-cache useMemory over timeEstimated memory used as a share of 48 GB physical memoryAll1 min5 min15 min100%50%0%10:32:1810:37:1810:42:18Memory used300 / 300 samplesClick or drag across the chart to inspect a sample.Inside your unified memoryKernel VM categories · estimates may differ from Activity MonitorApp / internal14.2 GB29.6%Wired4.1 GB8.5%Compressed3.1 GB6.5%Memory used · app + wired + compressed21.4 GB44.6%File / purgeable cache12.8 GB26.7%Free pages13.8 GB28.8%Physical memory48 GBPercentages are shares of 48 GB physical memory · Sample 10:42:18Largest memory workloadsFootprint where available, resident memory otherwiseSample 10:42:18Footprint or resident memoryL6.8 GBLumen Edit6 processesH5.6 GBHarbor9 processesK4.2 GBKite Browser23 processesF3.1 GBForge IDE14 processes2.4 GBkernel_task1 processExplore all processes* Marks a partial total when some measurements are unavailable.† Marks a total that includes resident-memory fallback.Step 03 Step 4. Find who is holding it
Scroll to Largest memory workloads. Apps are listed with their helpers, largest first. This is the list to work from if pressure is not Normal.
MemoryPhysical memory, compression, and the pressure on your Mac.Search or jump to…⌘KPauseRecordLive10:42:18Under half of 48 GB is in use; pressure is normal.Physical memory is shared by the CPU, GPU and Neural Engine. macOS can reclaim file cache when memory is needed.Pressure NormalSwap used 0 bytes · memory stored on disk21.4GBestimated used of 48 GBMemory used = app + wired + compressed012 GB24 GB36 GB48 GBApp / internal14.2 GB29.6%Wired4.1 GB8.5%Compressed3.1 GB6.5%File / purgeable cache12.8 GB26.7%Free13.8 GB28.8%Memory pressureNormalElevatedCriticalreported by macOS · every 2sNormal in every measured pressure sample · last 10 minShare in useof 48 GB44.6%estimated non-cache useMemory over timeEstimated memory used as a share of 48 GB physical memoryAll1 min5 min15 min100%50%0%10:32:1810:37:1810:42:18Memory used300 / 300 samplesClick or drag across the chart to inspect a sample.Inside your unified memoryKernel VM categories · estimates may differ from Activity MonitorApp / internal14.2 GB29.6%Wired4.1 GB8.5%Compressed3.1 GB6.5%Memory used · app + wired + compressed21.4 GB44.6%File / purgeable cache12.8 GB26.7%Free pages13.8 GB28.8%Physical memory48 GBPercentages are shares of 48 GB physical memory · Sample 10:42:18Largest memory workloadsFootprint where available, resident memory otherwiseSample 10:42:18Footprint or resident memoryL6.8 GBLumen Edit6 processesH5.6 GBHarbor9 processesK4.2 GBKite Browser23 processesF3.1 GBForge IDE14 processes2.4 GBkernel_task1 processExplore all processes* Marks a partial total when some measurements are unavailable.† Marks a total that includes resident-memory fallback.Step 04 Step 5. Act only if pressure is Elevated or Critical
If the strip is on Elevated or Critical, quit one or two apps from the top of that list, or close some browser tabs, and watch the strip come back to Normal.
If it is on Normal, there is nothing to fix, however full the bar looks.
02Good to know
The small print, in plain words
Note1 / 3
Swap is not an alarm
The line under the sentence shows swap, which is memory stored on disk. Some swap can stay in use long after a busy moment has passed. On its own it does not mean there is a problem now.
Note2 / 3
These numbers can differ from Activity Monitor
l/Activity shows the kernel's own memory categories and says they are estimates. Apple's app groups them a little differently.
Note3 / 3
App totals do not add up to the Mac total
Apps share some memory with each other, so the same pages can be counted in two rows.
03Keep going
