Mac

Mac says it's out of application memory on Tahoe

Fix "Your system has run out of application memory" on macOS Tahoe (macOS 26) — the autofill bug, the Electron app memory leak, and how to tell when you actually need more RAM, using the built-in Memory Pressure graph.

Read Memory Pressure, not Memory Used

Reference images and diagrams. Click any image to view full resolution.

Original concept diagram (not vendor copyright). 'Memory Used' looks high on every healthy Mac because macOS caches files in spare RAM. Judge by the Memory Pressure color instead: green = ignore the number, yellow = act soon, red = act now (this is when 'out of application memory' fires).

Activity Monitor Memory tab with a green Memory Pressure graph at the bottom, 64 GB physical memory, 37.58 GB memory used, 15.77 GB cached files, and 0 bytes swap used. — Activity Monitor → Memory: pressure is green even with 37.58 GB used — 15.77 GB of that is reclaimable cache and swap is zero — exactly the high-used-but-healthy case the diagram above describes. Process names blurred. First-party screenshot (macOS Tahoe 26.5).

Problem summary

I'm here because my Mac keeps showing "Your system has run out of application memory" on macOS Tahoe (macOS 26) — it tells me to force-quit apps, everything beachballs, and it happens even on a Mac with plenty of RAM. On Tahoe this is usually one of two confirmed software bugs that slowly leak memory, not a sign you're short on RAM. This page shows you how to read the Activity Monitor Memory Pressure graph to confirm what's really happening, then the exact fix for each bug — no "memory cleaner" app required.

Operator snapshotEvidence first

First proof

Open Activity Monitor → Memory and read the Memory Pressure graph colour.

Screen to open

defaults write -g NSAutoFillHeuristicControllerEnabled -bool false

Expected signal

Green or yellow pressure means macOS is coping — the error is a leak bug, not a RAM shortage.

Stop boundary

Revert the default if it changes nothing — don't leave a no-op override in place.

Layer path

1"Your system has run out of application memory" is macOS telling you it can no longer satisfy memory requests — but on macOS Tahoe the cause is almost always a leak (memory taken and never returned) rather than a real shortage. The stack to reason about is: the app or system process that's leaking, the memory-compressor/swap layer macOS uses to cope, and the Memory Pressure signal that tells you which of those is actually in trouble.

2The single most important instrument is the Memory Pressure graph in Activity Monitor, not the 'Memory Used' number. macOS deliberately fills idle RAM with cache and reports it as used, so 'Memory Used' is almost always high and tells you nothing. Pressure (green/yellow/red) is the real gauge of whether the system is coping.

3On Tahoe there are two distinct, confirmed leak bugs that produce this error: a system-level autofill heuristic that leaks slowly across the whole machine, and an Electron framework leak via the `_cornerMask` private API that bloats GPU/WindowServer memory whenever an Electron app draws rounded corners. They're fixed in different places (a macOS default vs an app update), so identifying which one you have decides the fix.

Runbook

Step-by-step runbook

Start here. Do each check in order, compare it to the expected result, and stop when the evidence explains the failure or the safe stop point applies.

Read the real signal

Check: Open Activity Monitor → Memory and note the Memory Pressure colour and swap.

Expected result: You know whether macOS is coping (green/yellow = leak) or genuinely strained (sustained red).

If not: If pressure is green/yellow, ignore the 'Memory Used' number and go leak-hunting.

Pin the culprit

Check: Sort by Memory and watch for a process that grows and never releases.

Expected result: You can tell an Electron-app leak from the system-wide autofill creep.

If not: If no single app grows but the error fires, treat it as the system autofill bug.

Apply the matching fix

Check: Set `NSAutoFillHeuristicControllerEnabled` false for the system creep; update Electron apps for an app leak.

Expected result: The leak source is removed at its actual layer (a macOS default vs an app update).

If not: If the autofill default changes nothing, revert it and focus on the specific app.

Flush with a restart

Check: Restart the Mac rather than force-quitting, so already-leaked memory is released.

Expected result: Memory begins from a clean baseline and stays flat with the fix in place.

If not: If it refills fast post-restart, capture the growing process and treat it as the single culprit.

Confirm, then judge RAM honestly

Check: Watch Memory Pressure over a normal day's real workload.

Expected result: Green/yellow confirms the bug is fixed; sustained red under real work is the only true RAM signal.

If not: If you do hit sustained red, reduce concurrent heavy apps and plan RAM into your next Mac (Apple Silicon RAM isn't upgradeable).

Decision tree

If: Memory Pressure is green/yellow but the error still fires.

Then: A leak bug, not a RAM shortage — the machine has memory, something won't give it back.

Action: Identify whether it's the system autofill heuristic or a specific Electron app, then apply the matching fix.

If: One Electron app keeps growing and is on an old Electron build.

Then: The `_cornerMask` private-API GPU/WindowServer leak.

Action: Update the app to a build on Electron 38.2.0 / 37.6.0 / 36.9.2+; quit it when idle until then.

If: No single app stands out, but memory creeps up across the whole system.

Then: The macOS 26 autofill heuristic leak.

Action: Set `NSAutoFillHeuristicControllerEnabled` to false, relaunch apps, and restart to flush what already leaked.

Safe stop: Revert the default if it changes nothing — don't leave a no-op override in place.

If: Memory keeps filling even right after a clean restart with almost nothing open.

Then: An aggressive, specific leak (a single misbehaving app or extension).

Action: Find the growing process in Activity Monitor and update, replace, or remove it.

If: Memory Pressure stays red for long stretches during ordinary real work, with no leak present.

Then: A genuinely RAM-constrained Mac.

Action: Close heavy apps you don't need; since Apple Silicon RAM is on-package, plan it into your next Mac rather than expecting an in-place upgrade.

Evidence

Evidence table

Symptom	Evidence to collect	Likely layer	Next action
Error fires on a Mac with plenty of RAM; pressure is green/yellow.	Activity Monitor shows high 'Memory Used' but non-red pressure.	Leak bug, not a shortage (misreading 'Memory Used').	Judge by pressure; find and fix the leak rather than adding RAM.
One Electron app's memory climbs for hours and never falls.	That app is on an Electron build older than 38.2.0 / 37.6.0 / 36.9.2.	Electron `_cornerMask` GPU/WindowServer leak.	Update the app; quit it when idle as a stopgap.
Whole-system creep with no obvious single offender.	Memory recovers after setting NSAutoFillHeuristicControllerEnabled false + relaunch.	macOS 26 autofill heuristic leak.	Keep the default set; restart to flush already-leaked memory.
Beachballs and the error return minutes after a clean restart.	A specific process is visibly growing from boot.	Aggressive app/extension-level leak.	Identify and update/remove that process; don't just force-quit repeatedly.
Pressure pegged red during ordinary tasks even after fixes.	`vm_stat` shows heavy sustained swapping under real (not leaked) demand.	Genuine RAM constraint.	Reduce concurrent heavy apps; factor more RAM into the next Mac.

Reference

Commands and settings paths

Disable the leaking autofill heuristic

defaults write -g NSAutoFillHeuristicControllerEnabled -bool false

Where: Terminal on the Mac, then fully relaunch apps (or log out/in).

Expected: The system-wide memory creep stops; memory holds steady over time.

Failure means: If memory still climbs, the leak is app-specific, not this heuristic.

Safe next step: Revert with `defaults delete -g NSAutoFillHeuristicControllerEnabled` and hunt the specific app.

Watch memory paging in real time

vm_stat 5

Where: Terminal on the Mac, under light load.

Expected: Pageouts and compressions stay low and roughly flat.

Failure means: Steadily rising pageouts under light load indicate a leak, not real demand.

Safe next step: Correlate the rise with a process sorted by size in Activity Monitor.

Identify Electron processes to check for the leak

ps aux | grep -i electron

Where: Terminal on the Mac.

Expected: Lists the running Electron-based apps so you can check each one's version.

Failure means: If a listed app is on an Electron build older than 36.9.2/37.6.0/38.2.0, it's a leak suspect.

Safe next step: Update that app, or quit it when idle until a patched build ships.

Look for low-memory events behind the dialog

log show --predicate 'eventMessage CONTAINS "low swap"' --last 1h

Where: Terminal on the Mac (or filter Console.app for jetsam/low-memory).

Expected: Shows the jetsam/low-memory events that precede the 'out of application memory' dialog.

Failure means: Frequent events tie the dialog to a specific process or a system-wide creep.

Safe next step: Match the timing to the process you flagged, then apply the matching fix.

Hardware boundary

Hardware and platform boundary

Change only when

Plan more unified memory into your next Mac only if Memory Pressure stays red under real (non-leaked) work after both Tahoe leaks are fixed.
If you routinely run many heavy apps (large IDEs, VMs, big creative projects) at once, size memory for that workload at purchase — it can't be added later.

Evidence that matters

Unified memory capacity at purchase time, because Apple Silicon RAM is on-package and never user-upgradeable.
Keeping Electron apps current — the framework-level fixes ship in app updates, not in macOS.
Whether your real workload (judged by Memory Pressure, not 'Memory Used') actually saturates RAM.

Evidence that does not matter

The 'Memory Used' figure — it includes cache macOS will reclaim on demand.
Swap existing on its own — some compression and swap is normal and healthy.
A cleaner app's 'memory freed' number — it's a marketing figure, not a diagnosis.

Avoid

Installing memory-cleaner / RAM-booster apps — they purge caches macOS manages and tend to worsen performance.
Buying RAM or a new Mac on the strength of this error before ruling out both leak bugs.
Force-quitting apps in a loop as a 'fix' — it hides the leak instead of resolving it.

Related tool/checklist

Use the linked tool when you need a guided plan from your exact symptoms instead of a static checklist.

Backup plan builder

Last reviewed

2026-06-02 · Reviewed by HomeTechOps. Reviewed against Apple's Activity Monitor memory documentation and macOS update notes, Electron's release history for the macOS 26 `_cornerMask` GPU-leak fix, and 2026 reports of the two distinct Tahoe memory-leak bugs; centres the fix on reading Memory Pressure rather than 'Memory Used', and separates the system autofill heuristic leak from the Electron app leak so each gets its correct fix.

Sources/assumptions

Assumes a Mac on macOS Tahoe (macOS 26) showing the 'out of application memory' dialog; the two leak bugs and their fixes are based on 2026 community, Apple, and Electron reports current to mid-2026.
The Electron fix versions (38.2.0 / 37.6.0 / 36.9.2) are upstream; an individual app ships the fix only once it rebuilds on a patched Electron — verify in the app's release notes.
Apple Silicon memory is on-package and not user-upgradeable, so 'add RAM' is never an in-place fix; it only informs a future-Mac decision.

Source-backed checks

HomeTechOps turns official docs and conservative safety rules into a shorter runbook. These links are the source trail for the page direction.

Apple Support: macOS Tahoe 26 — what's included in the updates (KB 122868)Authoritative per-point-release version + date list for macOS Tahoe 26.x; cited to pin which point release a Time Machine / Wi-Fi / dock symptom maps to.Apple Support: View memory usage in Activity Monitor on MacUsed for reading the Memory Pressure graph (green/yellow/red) as the real memory signal rather than the 'Memory Used' number, and for what swap and cached files mean.Electron: ReleasesUsed to pin the Electron versions that fix the macOS 26 `_cornerMask` GPU/WindowServer memory leak (38.2.0 / 37.6.0 / 36.9.2 and later); individual apps inherit the fix only after rebuilding on a patched Electron.Eclectic Light (Howard Oakley): Dealing with slow, hot MacsUsed for the operator approach to a slow/hot Mac — kernel_task is a symptom; do not edit the IOPlatformPluginFamily kext (it can break thermal protection); root-cause the heat source.

Diagnostic rule

1. Check the simplest signal first.
2. Change one thing at a time.
3. Avoid unsafe electrical or data-loss steps.
4. Stop when the evidence says the risk moved.

FAQ

Does "out of application memory" mean I need more RAM?

Usually not on macOS Tahoe. Open Activity Monitor → Memory and look at the Memory Pressure graph: if it's green or yellow, macOS has memory under control and the error is a software leak bug, not a RAM shortage. Only sustained red pressure under genuinely heavy real work — with no leak present — points to needing more memory.

How do I fix the memory leak on macOS Tahoe?

There are two. For the system-level autofill bug, run `defaults write -g NSAutoFillHeuristicControllerEnabled -bool false` in Terminal and relaunch your apps. For Electron apps (Chrome, Slack, VS Code, Discord), update them — the fix landed in Electron 38.2.0, 37.6.0, and 36.9.2. Then restart to flush memory that already leaked.

Why is my 'Memory Used' so high even when nothing's open?

That's normal and healthy. macOS deliberately uses otherwise-idle RAM as cache to speed things up, and releases it the moment an app needs it. Judge memory by the Memory Pressure graph, not the 'Memory Used' total — high used + green pressure is exactly how macOS is supposed to behave.

Should I install a memory-cleaner app to fix this?

No. RAM-booster and memory-cleaner apps purge caches that macOS manages on its own, which usually slows the Mac back down moments later and can mask the real leak. The genuine fixes are the autofill workaround, updating Electron apps, and a restart — all built in and free.