My Mac is frozen - it won't do anything. What's the best fix?

A frozen Mac is a rare occurrence, but Macs (like all computers) run in cycles, and sometimes the software gets stuck in a loop. When this happens you may find an app, or the whole of Mac OS X, becomes unresponsive. Learning what to do with a frozen Mac will make you a happier Apple owner.

In this feature we look at what to do with a frozen Mac. Follow the steps in this feature to get your Mac unstuck, and working again.

See also:

How to fix a frozen Mac: Is the problem a single app, or the entire OS?

App Crash - Problem Report

The first thing to do is to determine whether the whole of OS X is affected, or just one app. OS X is a smart, modern operating system and the memory used by apps is managed by the OS X operating system.

For the most part, if a single application is the problem (typically because it's stuck in a loop and taking up too much memory) you'll be able to tell easily: you'll get an alert (something like the one pictured above) informing you that the app quit unexpectedly. If the Mac locks up without any alert, on the other hand, it's likely that the problem lies with the OS.

We'll deal with the latter scenario shortly, but in the former, you have two main options:

  • Click Reopen will start the app up again, and send a report to Apple.
  • Click OK dismisses the alert window.

How to fix a frozen Mac: Stop sending crash reports to Apple

OS X Privacy & Security

By default OS X sends a crash report to Apple whenever an application crashes. Apple uses this data to manage development of OS X and provide a more stable operating system (and more stable apps) in the future.

As an aside, if you aren't keen on sending app crash data to Apple, you can turn off the automatic report functionality in System Preferences:

  1. Open System Preferences.
  2. Click Security & Privacy.
  3. Click the Lock icon in the lower-left of the window and enter your Admin password
  4. Choose Privacy > Diagnostics & Usage.
  5. Deselect the Send diagnostic & usage data to Apple and Share crash data with app developers.
  6. Click the Lock icon again to close System Preferences.

Now when an Apple crashes you'll get a Reopen and Report button. Clicking Report will send a report to Apple; clicking Reopen will re-open the program.

See also: 10 steps to take when your Mac won't start up and How to fix and diagnose performance issues on a Mac

How to fix a frozen Mac: What to do if an app freezes

OS X Force Quit Application

Mac OS X quitting, and restarting the app, is the best way for OS X to handle a crash. A rarer - but also more annoying - problem is if an app simply ceases to function. Often you'll spot this because the app's menus and icons are unresponsive, and you may see the rainbow wheel, also known as the spinning wait cursor. It's also called the 'spinning beach ball', the 'spinning pizza of death' or just SPOD.

Here's what to do if you encounter a frozen app:

  1. Switch to another area of OS X. Click on another App window, or the desktop. Alternatively, press Command-Tab to switch to another app.
  2. Control-click the app icon in the Dock.
  3. Hold Option (Quit in the menu will change to Force Quit).
  4. Select Force Quit.

The app will be instantly closed. There are other ways to force an app to quit. If the Dock is unresponsive, press Command-Option-Esc to open the Force Quit Applications window. Choose an app from the list, and click Force Quit.

For more on Force-Quitting, take a look at: How to control-alt-delete on a frozen Mac: Use Force Quit to shut down OS X apps.

Force Quit a frozen OS X app

How to fix a frozen Mac: What to do if OS X itself is frozen (or if an app refuses to Force Quit)

If you cannot force quit an app, or if OS X is completely unresponsive, then follow these steps in order:

  1. Choose Apple Menu > Restart and click Restart.
  2. If you cannot interact with the Apple Menu, press Command-Control-Eject. This instructs OS X to restart immediately.
  3. If that doesn't work, press and hold the Power button on your Mac until it switches off. Press and release the power button to turn it back on again.

When you restart you may find the file you were working on is damaged or corrupted. You should try to recover what you can from it, and transfer any contents to a new file (then delete the file).

How to fix a frozen Mac: Finding the source of the problem

You should investigate the cause of the crash. If you encounter frequent freezes, check the following:

  • Check that you have enough free hard drive space in OS X.
  • Make sure you have used Updates in the App Store app to make sure OS X and your installed apps are up to date.
  • Update apps installed outside of the App Store manually. Each app usually has a check for updates feature.
  • If you are encountering frequent crashes, or freezes, you should update your software and then disconnect all your peripherals. Re-attach them one at a time to see if one of them is causing the problem.
  • Disable plug-ins. If you use apps with plug-ins, you should disable (or remove) them to discover if they are causing problems.
  • Use a Safe Boot by holding down the Shift key while starting up your Mac. This launches OS X without any additional processes and runs clean-up scripts.
  • Use Disk Utility's Repair Disk function to clean up any problems with your hard drive.
  • Run Apple Hardware Test. this is a special utility from the Apple Support Site that detects problems on your Mac.