Is the F3 key on your Mac not working as expected? Perhaps pressing F3 does nothing, opens the wrong function, or behaves differently when you connect an external keyboard.
The F3 key can perform different functions depending on your Mac model, keyboard and macOS settings. On many Apple keyboards, F3 opens Mission Control, which shows your open windows and desktops. On some keyboards, you may need to hold down the Fn or Globe key to use the standard F3 function.
If you use a Windows keyboard with your Mac, the function keys may behave differently again.
This guide explains what F3 does on a Mac, how to use it on a MacBook or external keyboard, and what to check when the key does not work.
Quick tip: If you want to see all your open windows, try pressing F3 on your Apple keyboard. If that does not work, continue with the troubleshooting steps below.
How to Fix the F3 Key on a Mac
Try these checks in order. The correct solution depends on whether you are using a MacBook keyboard, an Apple external keyboard or a third-party keyboard.
1. Check what F3 is supposed to do
On many Apple keyboards, F3 opens Mission Control, which displays your open windows and desktops.
Try pressing F3 and see whether Mission Control opens.
If nothing happens, continue to the next step.
2. Try the Fn or Globe key
Some Mac keyboards use the function keys for special features, while others can use them as standard F1–F12 keys.
Try pressing Fn + F3 or Globe + F3, depending on your keyboard.
The result depends on your Mac model, keyboard and settings, so this may not be necessary on every device.
3. Check the macOS function-key setting
On supported versions of macOS:
- Open the Apple menu.
- Select System Settings.
- Open Keyboard.
- Look for the setting that controls whether F1, F2 and other keys are used as standard function keys.
- Check whether the setting matches how you want the keyboard to behave.
When standard function keys are enabled, you may need to hold Fn or Globe to use the special features printed on the keys.
The wording and location of this setting can vary between macOS versions.
4. If you are using an external keyboard
If F3 works on your MacBook but not on an external keyboard, check the external keyboard first.
- Confirm that the keyboard is compatible with your Mac.
- If it has a Mac/Windows mode switch, select the appropriate mode.
- Check whether it has an Fn Lock setting or a different function-key layout.
- If it connects by USB, try another USB port or disconnect and reconnect it.
- If it is wireless, check its battery or charge level and reconnect it.
If other keys work but F3 does not, consult the keyboard manufacturer’s instructions for its function-key behaviour.
5. Check Mission Control settings
If F3 is intended to open Mission Control but does not, open System Settings and search for Mission Control or Keyboard Shortcuts.
Check whether Mission Control has a keyboard shortcut assigned and whether that shortcut conflicts with another application.
6. Restart and test again
Save your work, restart your Mac and test F3 again.
If the key still does not work, try another keyboard if one is available. This can help determine whether the problem is with the keyboard or macOS.
7. When to seek further help
If F3 fails on multiple keyboards, or other keyboard functions are also failing, the problem may require further macOS or hardware troubleshooting.
Record your Mac model, macOS version and keyboard model before seeking help. These details make it easier to identify the correct solution.
Need More Help With Your Mac?
If your keyboard is still not working correctly, these related guides may help:
- Mac and computer support from iTech WA — practical help with Mac computers, peripherals and common technology problems.
Need help with your computer or technology?
iTech WA provides friendly, professional IT support for homes and small businesses in Bridgetown and the South West.
With more than 40 years of IT experience, I provide practical, plain-English advice and personal service.
Friendly, professional IT support that comes to your door.
