Too many apps open? How many is too many on a Mac

There is no number of open apps that is too many on a Mac. Fifty idle apps can be fine, and three busy ones can bring the machine to a crawl. What counts is what the apps are doing and whether your memory is under strain. An app that is open and doing nothing costs memory but almost no processor time, so the real limit is memory pressure, not the count in your Dock.

Why the count does not matter much

Think of each open app as two separate costs.

The first is memory. Every open app holds some memory for its windows, documents and whatever it has loaded. This cost is there whether you touch the app or not. It adds up, and it is the one that eventually becomes a problem.

The second is processor time. An app that is sitting idle, with no video playing, no sync running and nothing being calculated, uses close to none. It is open but it is not working. An app that is syncing, rendering, scanning or refreshing uses a lot, and that is what makes everything else feel slow.

This is why “I have too many apps open” is often the wrong diagnosis. If your Mac is slow with ten apps open, the cause is probably one of them, not all ten. And if your Mac is fine with thirty, the count was never the problem.

What happens when memory runs short

macOS manages memory actively. Before it runs out, it compresses memory that has not been used recently, and if that is not enough it moves some of it to the disk. Both keep the Mac working, and neither is a fault. You only notice when there is more asked of memory than the Mac can comfortably give: apps pause for a moment when you switch to them, the beach ball appears, and everything feels sticky.

That strain has a name, memory pressure, and it is the number to watch instead of an app count. Low pressure means there is plenty of room, whatever the number of apps. High, sustained pressure means the Mac is struggling to keep everything you have open ready to use. Memory pressure on a Mac: when you actually need more RAM explains how to read it.

In Foreman, memory pressure is on the Performance page: choose Memory in the list on the left and you get a live graph with the pressure shown, and below it the apps using the most memory. The menu bar panel also shows memory at a glance. Checking takes a few seconds, and it tells you whether the problem is real.

How to tell if you have too many open

Instead of counting, run through these.

1. Does anything feel slow? If switching between apps is instant and nothing stutters, you are not over the limit, however many apps are open.
2. Is memory pressure high? If it stays high while you work, you have more open than your Mac can comfortably hold.
3. Is one app using a lot of processor time? Sort by CPU. If one app, or its helpers, is far ahead of the rest, close or slow that one, and the count no longer matters.

If the answer to the first question is no, stop there. There is nothing to fix.

What to close first

If memory pressure is high and you need to free some room, close apps in this order:

• Apps you have finished with. The ones you opened an hour ago for a single task and forgot.
• Apps holding the most memory. Sort the Memory column from high to low. A browser with many tabs, a design tool with a large file open or a virtual machine is often at the top. In Foreman, apps are grouped with their helpers, so a browser’s tabs add up to one number instead of being spread over many lines.
• Apps with many windows. Each open window or document is something the app keeps loaded.

Quit the normal way with Command-Q, or use End Task in Foreman, which does the same thing: it asks the app to quit so it can offer to save your work. Only force quit an app that is not responding.

What about apps you need open?

Some apps you want to keep open all day: mail, chat, a calendar, a music player. Closing and reopening them is a nuisance, and they are often not the problem anyway, because most of the day they are idle.

If one of them is busy in the background even though you are not using it, Efficiency Mode is meant for exactly that. It lets the app stay open but holds it to about a quarter of the processor time it would take while it is in the background. In front, or while it is playing sound, it runs at full speed. It is remembered for that app until you turn it off. It works on processor time and does not free memory, so do not count on it to lower memory pressure, but it is a good fit for the busy-but-not-needed case. How to stop one app from slowing down everything else on your Mac covers it.

Apps you do not see

The Dock and the Force Quit window (Option-Command-Escape) show only regular apps, the ones you think of as open. A lot more is running: background processes, helpers and macOS’s own services. Those count towards memory too. A Mac with only a handful of apps open can still be busy because of what is running behind them. How to find out what’s running in the background on your Mac shows how to see them.

It also means a clean restart can help more than closing apps one by one. If your Mac has been on for a long time and is slow, restarting resets all of it at once.

When more apps really is too many

There is a point where the answer is yes. If memory pressure stays high even after you close what you do not need, and you really do use all those apps together, your Mac does not have enough memory for the way you work. That is a hardware limit, and the choice is to work with fewer apps at a time or to move to a Mac with more memory.

Short of that, you can keep as many apps open as you like. Check how the Mac feels, look at memory pressure, and close what is heavy. Foreman shows both in one place, and it is free for 24 hours, then $12 once for up to 3 Macs.