What Not responding means on a Mac, and how long to wait

Not responding means macOS has noticed that an app has stopped handling the events it is sent, such as clicks, keystrokes and window updates. Often the app is busy with a long task and comes back by itself, so for a minute or two the right move is to wait. If it is still stuck after a few minutes, or the busy work is clearly over, force quit it and reopen it.

Below: what the flag really means, how long to wait, what to try before force quitting, how to force quit, and how to see it all in one place.

What the flag means

Every Mac app has a main loop that picks up events: you click, type or scroll, and the app reacts. macOS keeps an eye on that loop. If an app does not respond for long enough, macOS marks it as hung. You usually see this as the spinning beach ball over the app, and in the Force Quit window the app’s name is followed by “(not responding)”.

The flag does not mean the app has crashed. A crashed app disappears, and macOS may offer to report it. A not responding app is still there, still using memory, and may still be working. It has just stopped answering the system while it does something else.

There are two broad reasons.

• It is busy. The app is doing one long job on the main loop: opening a very large file, searching a huge library, exporting, loading a big web page, or waiting for a network drive that is slow to answer. It is not broken, and it will answer when the job ends.
• It is stuck. The app is waiting for something that will never arrive, or has hit a bug and is looping. It will not recover without your help.

From outside, these look the same, which is why the question of how long to wait has no exact answer. The spinning beach ball on a Mac: what it means and what to do covers the same ground from the other side.

How long to wait

There is no official number, so use the situation as your guide.

• A few seconds. Normal. Heavy jobs make apps pause, and most come back at once. Do nothing.
• Up to a minute or two. Wait, if you know the app is doing something large, such as exporting, importing, converting or opening a big file. Check whether the Mac is working: if the processor or disk is busy with that app, it is likely still going.
• A couple of minutes with nothing busy. If the app is flagged and the Mac is quiet, with the app using almost no processor, it is probably stuck. Nothing is happening that waiting could finish.
• A long job you started. Give it longer, within reason. Some jobs take many minutes. The thing to check is activity, not the clock.

The check that settles it is whether the app is using the processor or the disk. A flagged app that is working hard is probably still busy. A flagged app at zero is probably stuck. In Terminal, top -o cpu shows processor use per process, and you can look for the app by name. Press q to leave.

Try this before force quitting

You lose unsaved work when you force quit, so spend one minute on the gentler options.

1. Wait and watch. Move the pointer. If the beach ball vanishes, you are done.
2. Look for a hidden dialog. If the app ignores clicks but shows no beach ball and is not marked as not responding, it may be waiting on a question in a window behind others, such as a save prompt. Click its icon in the Dock, or switch to it with Command-Tab, to bring it forward.
3. Quit other heavy apps. If the Mac is short of memory or the processor, the app may be starved, and it will recover when there is room.
4. Check an external drive or network folder. If the app was opening or saving a file on a drive or a network share that has gone away, it can hang until macOS gives up waiting. Reconnecting the drive or the network often lets it recover.
5. Try a normal quit. Command-Q asks the app to quit, and a responsive-enough app will offer to save. If it does nothing, move on.

How to force quit

macOS has this built in.

1. Press Option-Command-Escape to open the Force Quit window. You can also choose Force Quit from the Apple menu.
2. Select the app in the list.
3. Click Force Quit, and confirm.

An app that has stopped responding has “(not responding)” after its name, so it is easy to pick out, and the confirmation reminds you that you will lose any unsaved changes. After a force quit, reopen the app. Many restore your windows, and some apps recover unsaved documents from an autosave, but you cannot count on it. What you lose is anything that was not saved, and the app may open its last saved state. If you are working in a document, check the app’s own recovery before you throw anything away. Quit vs force quit on a Mac: what you lose with each goes through the difference.

How Foreman shows it, and what it does

Foreman is a Task Manager for macOS. On its Processes page, a row can read “Not responding” when macOS has marked the app as hung, next to the app’s CPU, memory, disk, network and GPU figures. That is the useful pairing: you see the flag and the activity on the same row, so you can tell a busy app from a stuck one without opening a second tool.

To deal with it, select the app and choose End Task, or right-click it. For an app that macOS has marked Not responding, End Task force quits it at once, because asking it nicely would not work. If the app is still open after a moment, Foreman brings it forward, since it may be asking about unsaved changes, and offers Force Quit. Force Quit on an app with windows asks first, with a reminder that you will lose any unsaved changes.

For an app that is not flagged, End Task works the other way round: it asks the app to quit the normal way, as Command-Q does, so it can offer to save, and pressing it again within a minute forces it. If you want the app back straight away, Restart in the right-click menu quits it and opens it again, behind Foreman, so you stay where you were instead of being switched to the app.

Control-Shift-Escape opens Foreman from any app. For a Windows user, that is the same shortcut and the same idea. Foreman is $12 once for up to 3 Macs and free for 24 hours.

One thing it does not do: it does not warn you with alerts when an app starts to hang, so you see the flag when you look at the Processes page.

When it keeps happening

An app that hangs once is a one-off. An app that hangs every day is telling you something.

• Update it. A newer version may fix the hang. Check the app’s own update option.
• Free some room. If memory pressure is high most of the day, hangs are more frequent.
• Look at what it is waiting on. Network drives, large libraries and plug-ins are common causes.
• Restart the Mac if several apps hang together, because the cause may sit lower than any one app.

If the whole Mac stops responding rather than one app, that is a different problem, and what to do when your whole Mac freezes is the page to read.