---
id: mac-storage-basics.what-does-out-of-application-memory-mean
url: https://storagestudio.us/faq/mac-storage-basics/what-does-out-of-application-memory-mean
category: "Mac storage basics"
subcategory: "Memory, swap and speed"
question: "What does \"Your system has run out of application memory\" mean?"
alt_questions:
  - "out of application memory mac"
  - "force quit applications memory warning"
  - "mac ran out of memory"
  - "application memory error macbook"
  - "system run out of memory fix"
  - "What should I do when my Mac says \"Your system has run out of application memory\"?"
  - "Mac out of application memory warning"
  - "Force Quit Applications window keeps appearing"
  - "run out of application memory mac fix"
  - "Can Storage Studio fix out of memory errors?"
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."
tags: ["memory", "swap", "error", "macos", "slow mac"]
related: ["https://storagestudio.us/faq/mac-storage-basics/what-are-swap-files-on-a-mac"]
applies_to: "all"
last_reviewed: 2026-10-01
---

# What does "Your system has run out of application memory" mean?

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.

1. In the dialog or Activity Monitor's Memory tab, quit the app using the most memory.
2. Free some disk space so macOS has room to swap.
3. Restart if things stay sluggish.

If the same app keeps doing it, update it or report it to its developer.