Your Mac: “Your system has run out of application memory” — How to diagnose & clear application memory
Quick fix (for voice search): “How to clear application memory on Mac?” — Open Activity Monitor → Memory, quit heavy apps, free disk space, restart. Read on for exact steps, causes, and prevention.
What is “application memory” on a Mac?
Application memory refers to the RAM that running apps and processes allocate to store code and active data. macOS manages physical RAM, plus virtual memory (swap files) on disk. When RAM fills, macOS uses swap — a disk-based fallback that keeps the system running but is much slower than RAM.
Memory pressure is macOS’s internal indicator of how strained RAM and swap are. Low memory pressure means the system is fine; high memory pressure means apps will slow, hang, or trigger the “Your system has run out of application memory” alert.
Understanding application memory helps you decide whether the fix is a simple cleanup (close apps, clear caches) or a hardware change (add RAM or move to a Mac with more memory). It also clarifies why free disk space matters: swap files require free disk to grow.
Why macOS shows “Your system has run out of application memory”
That message appears when the combination of used RAM and available swap cannot satisfy app allocations. Typically you’ll see slowdowns, beachballing, or apps quitting unexpectedly. The operating system is telling you it cannot allocate memory safely without jeopardizing stability.
Common triggers include: many browser tabs and heavy apps (e.g., Chrome, Photoshop), memory leaks (an app that continuously consumes more RAM), insufficient free disk space for swap, or too little installed RAM for your workflows.
macOS can sometimes mask issues via compressed memory, but compression has limits. When compression and swap are exhausted, the message is effectively a protective failure mode: take action or risk data loss if an app crashes while writing data.
Step-by-step: How to clear application memory on Mac (safe and fast)
Follow these safe, prioritized steps to clear application memory and recover a usable system quickly. Each step includes why it helps so you can choose the least disruptive option first.
- Check Activity Monitor (Memory tab) — Find memory hogs and memory pressure.
- Quit heavy apps — Save work and quit the largest offenders; Force Quit if unresponsive.
- Free disk space — Ensure at least 10–20% free disk for swap growth.
1) Diagnose with Activity Monitor
Open Applications → Utilities → Activity Monitor and click the Memory column. Sort by Memory to see which apps use the most RAM. At the bottom, look at Memory Pressure: green is OK, yellow is warning, red is critical.
Also check “Swap Used” and “Compressed” values — large swap indicates RAM exhaustion. Identify apps showing rapidly increasing memory usage; those may have leaks or runaway processes.
If a single app constantly climbs, select it and choose Quit → Force Quit after saving work. For system processes that misbehave, a reboot is usually safer than forcing system daemons.
2) Quick runtime actions (no reboot)
Close browser tabs, especially sites with video or heavy JavaScript. Quit large apps like virtual machines, audio/video editors, and design software. Check login items (System Settings → General → Login Items) and temporarily disable nonessential helpers.
Clearing caches can help transiently. For Safari, clear History & Website Data. For other apps, use their built-in cache-clearing options. Avoid third‑party cleaner tools unless you trust them.
If you cannot interact normally, press Command+Option+Esc, force quit the worst offenders, then re-check Activity Monitor. If the system is too unresponsive, restart (Apple menu → Restart) — a clean reboot frees RAM and clears swap files.
3) When to use Terminal & advanced checks
For advanced users: check live memory stats with Terminal commands like vm_stat and memory_pressure (if present). These tools show page ins/outs and pressure signals for deeper diagnostics.
A now-legacy command was sudo purge, which tried to free file system caches and inactive memory; it may not exist on recent macOS versions. Use with caution and only if you know what the command does.
Prefer monitoring and closing offenders rather than forcing low-level operations. If a developer tool or script is responsible, restart the offending background service or update the app.
Prevention and long-term fixes
Short-term cleanup is fine, but recurring messages mean you should adopt longer-term fixes. Start by keeping your system and apps updated — many memory leaks are fixed in updates. Monitor your typical workload: if you routinely use heavy apps simultaneously, plan for more RAM.
Free disk space is crucial because macOS relies on swap. Keep at least 10–20% of your startup drive free; SSDs are faster but still far slower than RAM. Offload large files to external drives or cloud storage to preserve internal disk space.
If your Mac supports user-upgradable RAM (older MacBook Pros, Mac minis, iMacs), adding RAM is the most effective long-term fix. For non-upgradable Macs (newer sealed MacBook Air/Pro and Apple Silicon Macs), choose a model with more RAM when upgrading hardware.
Troubleshooting checklist (quick reference)
Use this checklist as your go-to when you see the memory warning. Try items in order from least disruptive to most.
- Activity Monitor → identify and quit memory-heavy apps; check Memory Pressure.
- Close browser tabs, quit background apps, disable unused login items.
- Free disk space (move large files, empty Trash) to allow swap growth.
- Restart the Mac to clear RAM and temp files when system is very slow.
- If persistent: update apps/macOS, test in Safe Mode, consider RAM upgrade.
When to contact support or use deeper diagnostics
If you routinely see the error under normal usage after doing the above, you likely have either a memory leak in an app or genuinely insufficient RAM for your workload. Use Safe Mode and create a new user account to isolate whether the problem is user-specific or system-wide.
If diagnostics point to hardware issues (unexpected kernel_task behavior, unusual memory errors), contact Apple Support or an authorized service provider. For persistent app-related issues, contact the app vendor with Activity Monitor logs and steps to reproduce.
Developers can collect crash logs and memory profiles using Instruments (Xcode) to track down leaks. If you want a community-driven resource for technical details, see the GitHub discussion on application memory behavior: application memory on Mac.
Recommended commands & tools (advanced)
Use these only if comfortable with Terminal and system tools. Most users should stick to Activity Monitor and the GUI steps above.
vm_stat— view virtual memory statistics (page ins/outs).memory_pressure— shows pressure and reclaim metrics (if available).- Activity Monitor — the primary GUI tool to inspect memory and quit processes.
Third‑party utilities such as CleanMyMac advertise memory freeing; use them cautiously — they often automate actions you can do manually and may add persistent background helpers that increase memory usage. Always read reviews and prefer tools with a good reputation.
Backlinks & resources
Developer/community reference on memory behavior: application memory on Mac.
Apple support pages about memory and swap are also useful; search Apple Support for “memory pressure mac” and “Activity Monitor memory”.
FAQ (3 selected user questions)
How do I clear application memory on my Mac quickly?
Open Activity Monitor → Memory tab, sort by Memory, quit or Force Quit large apps, close browser tabs, and free disk space so macOS can use swap. If the system remains sluggish, restart to clear RAM and temporary swap files.
What causes the ‘Your system has run out of application memory’ message?
It happens when RAM + available swap can’t meet active allocations. Causes include too many memory-intensive apps, memory leaks, or insufficient free disk for swap. Check Memory Pressure and Swap Used in Activity Monitor to confirm.
Can I fix the error without upgrading RAM?
Often yes: quit heavy apps, reduce background processes, clear caches, keep 10–20% free disk space, and update problematic software. If you still hit the limit in typical use, a RAM upgrade or higher‑RAM Mac is the reliable solution.
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