Memory
Compressed memory
Memory macOS has squeezed to make room before resorting to swap.
What it is
When memory gets tight, macOS compresses data that apps aren't actively using, so more fits in physical memory. Compressing is far faster than writing to disk.
Activity Monitor shows the total as "Compressed" in the Memory tab.
Should you worry?
No. It's macOS doing its job. A large and growing compressed figure simply tells you memory pressure is building.
What you can do
- Treat it as an early warning: close what you don't need before pressure turns red.