Mac storage basics · Memory, swap and speed
What does "Your system has run out of application memory" mean?
Short answer: macOS ran short of memory and swap, often from one app using too much memory or very low free disk space. Quit the biggest app, free some disk space and restart if needed.
macOS has run short of memory and swap combined, so it asks you to quit something. It's usually caused by one app using far too much memory, very low free disk space (which limits swap), or both.
- In the dialog or Activity Monitor's Memory tab, quit the app using the most memory.
- Free some disk space so macOS has room to swap.
- Restart if things stay sluggish.
If the same app keeps doing it, update it or report it to its developer.