MacBook Function Keys Not Working? 8 Fixes to Try in 2026

Function keys on a MacBook have two modes, and if you don’t know about the toggle that switches between them, you’ll spend a lot of time confused. That’s where most of these “my F-keys are broken” reports come from. The fix usually takes about 30 seconds.

Work through the fixes below in order if you’re not sure what’s wrong. If you already have a lead, jump straight to the matching section using the table below.

Before You Start: Understanding How MacBook Function Keys Work

This is worth reading even if you’re in a hurry, because it changes how you interpret everything else.

MacBook function keys (F1 through F12) have two personalities:

Media/system controls: Adjust brightness, volume, Mission Control, Launchpad, and so on. These are the symbols printed on the keys.
Standard function keys: The traditional F1, F2, F3… inputs that apps and games expect when they say “press F5 to refresh” or “use F-keys for shortcuts.”

A single toggle in keyboard settings controls which mode is active. By default on most MacBooks, the keys act as media controls, so pressing F1 dims your screen instead of sending an F1 signal to your app. Holding Fn (or Globe on newer MacBooks) temporarily flips to the other mode.

Once you know this, about half of all function key complaints make immediate sense.

Quick Diagnosis

Run through this before diving into the fixes:

Try holding Fn or Globe while pressing a function key, does the behavior change?
Test in a different app, do the keys work in one app but not another?
Did the problem appear after a macOS update or a new app install? That narrows things down fast.
Test all 12 keys, if only one or two are dead, that points toward a hardware issue or a specific shortcut conflict rather than a system-wide setting.

Symptoms and Fixes at a Glance

Symptom	Likely Cause	Jump To
F-keys control brightness/volume instead of app functions	Standard function key toggle is off	Fix 1
Fn or Globe key doesn’t switch modes	Fn key behavior misconfigured	Fix 2
Keys work in some apps but not others	System shortcut conflict	Fix 3
Keys stopped working after installing an app	Third-party app intercepting input	Fix 4
Keys feel slow or need a long press to register	Slow Keys is enabled	Fix 5
All keys stopped working after a macOS update	NVRAM corruption or update reset settings	Fix 6 or Fix 7
One or two specific keys are completely dead	Hardware issue	Fix 8

Fix 1: Toggle “Use F1, F2, etc. Keys as Standard Function Keys”

This solves the problem for most people. If your function keys are adjusting screen brightness when you want them to send F1 or F2 signals to an app, this is the setting to change.

On macOS Ventura, Sonoma, or Sequoia:

Click the Apple menu () in the top-left corner and choose System Settings.
Click Keyboard in the sidebar.
Find the toggle labeled Use F1, F2, etc. keys as standard function keys and turn it on.

macOS System Settings Keyboard panel showing the "Use F1, F2, etc. keys as standard function keys" toggle and the "Press Globe key to" dropdown

On macOS Monterey or earlier:

Click the Apple menu and choose System Preferences.
Click Keyboard, then select the Keyboard tab.
Check the box labeled Use F1, F2, etc. keys as standard function keys.

macOS System Preferences Keyboard panel on Monterey or earlier showing the "Use F1, F2, etc. keys as standard function keys" checkbox

Verification: Press F1 in any app. It should now send a standard function key signal instead of dimming your screen. To control brightness or volume, hold Fn or Globe while pressing the F-key.

Note for Windows switchers: This setting is the Mac equivalent of the “F Lock” key on some Windows keyboards. Turn it on and your function keys behave exactly as you’d expect from a PC.

Fix 2: Use the Fn / Globe Key to Switch Modes on the Fly

You don’t always need to change the system setting. The Fn key (or Globe key on MacBooks released after 2019) lets you temporarily flip function key behavior without opening System Settings at all.

If standard function keys are your default (Fix 1 toggle is on): Hold Fn while pressing a key to access brightness, volume, and other controls.
If media controls are your default (Fix 1 toggle is off): Hold Fn while pressing a key to send an F1, F2, etc. signal.

If the Fn / Globe key itself isn’t doing what you expect, check its behavior setting:

Go to System Settings > Keyboard (macOS Ventura or later) or System Preferences > Keyboard (Monterey or earlier).
Find the dropdown labeled Press Globe key to or Press Fn key to, the label depends on your MacBook model.
Make sure it’s set to something that fits your workflow. The options are typically Change Input Source, Show Emoji & Symbols, Start Dictation, or Do Nothing.

One thing worth knowing: the Globe key’s mode-switching function (holding it while pressing F1–F12) is separate from this “press alone” behavior. Holding Globe always toggles the function key mode, regardless of what the dropdown is set to.

For a full breakdown of everything the Globe key can do, see Apple’s guide on using the Fn and Globe key.

Fix 3: Check for macOS System Shortcut Conflicts

This is why function keys work in some apps but not others. macOS reserves several function keys for system-level actions: F3 opens Mission Control, F4 opens Launchpad, F11 shows the desktop. These system shortcuts take priority. So if your video editing app expects F11 to trigger something, macOS intercepts that keypress first and the app never sees it.

Here’s how to find and fix the conflicts:

Go to System Settings > Keyboard (or System Preferences > Keyboard on Monterey or earlier).
Click Keyboard Shortcuts….
In the left sidebar, check these sections:
- Mission Control
- Launchpad & Dock
- Spotlight
Look for any F-key assignments that overlap with the keys you need.
Uncheck the checkbox next to any conflicting shortcut, or click the key combination and reassign it.

Keyboard Shortcuts panel with Mission Control section selected, showing F-key assignments like F3 for Mission Control and F11 for Show Desktop

Keyboard Shortcuts panel with Spotlight section selected, showing any function key assignments that could conflict with app shortcuts

Verification: After unchecking a conflicting shortcut, switch to the app that was having trouble and test the function key again.

Tip: Apps like Microsoft Excel, Final Cut Pro, and Adobe Premiere have their own internal shortcut settings. If macOS shortcuts aren’t the issue, check the app’s own Preferences or Settings for keyboard shortcut options.

Fix 4: Check for Third-Party Keyboard Apps Intercepting Your Keys

Apps like Karabiner-Elements, BetterTouchTool, and Keyboard Maestro work by intercepting keypresses before they reach anything else on your system. That’s what makes them powerful, and it’s also what makes them a likely culprit when function keys start behaving strangely after an install.

Step 1: Quit any keyboard customization apps.

Check your <a href=”https://www.switchingtomac.com/mac-menu-bar-missing-or-not-working-12-fixes-to-try/” >menu bar</a> for icons from Karabiner-Elements, BetterTouchTool, or Keyboard Maestro. Right-click the icon and choose Quit. Then test your function keys.

Step 2: Check Input Monitoring permissions.

On macOS Ventura and later, you can see exactly which apps have permission to monitor keyboard input:

Go to System Settings > Privacy & Security.
Scroll down and click Input Monitoring.
Review the list. If you see an app you don’t recognize or no longer use, toggle it off or click the minus (–) button to remove it.

System Settings Privacy & Security data-lazy-src=

Verification: After quitting the app, test your function keys. If they’re back to normal, the culprit is confirmed. You can then reopen the app and remove the specific rule that was causing the conflict, rather than uninstalling the app entirely.

Fix 5: Turn Off Slow Keys in Accessibility Settings

Slow Keys is an Accessibility feature that requires you to hold a key for a set duration before macOS registers the press. It exists to help users who accidentally brush keys. If it’s on and you’re tapping function keys quickly, they’ll feel completely dead, because the keypress just never meets the threshold.

Go to System Settings > Accessibility (or System Preferences > Accessibility on Monterey or earlier).
Scroll down and click Keyboard under the Motor section.
Check whether Slow Keys is turned on. If it is, toggle it off.

System Settings Accessibility data-lazy-src=

Verification: Tap a function key with a normal, quick press. It should register immediately.

Also worth checking: While you’re in Accessibility > Keyboard, look at Sticky Keys too. Sticky Keys changes how modifier keys behave and can cause confusing interactions with function keys if it’s accidentally enabled.

Fix 6: Reset NVRAM (Intel Macs Only)

This fix applies to Intel-based MacBooks only. If you have an Apple Silicon Mac (M1, M2, M3, or M4), skip to Fix 7. Apple Silicon Macs handle this memory automatically, so there’s no manual reset to perform.

NVRAM is a small block of memory your Mac uses to store certain settings, including some keyboard preferences. Corruption here, usually from a crash or a bad update, can cause function keys to behave in ways that make no obvious sense. Resetting it clears everything out and lets macOS rebuild from scratch.

How to reset NVRAM on an Intel MacBook:

Shut down your MacBook completely.
Press the power button, then immediately hold Option + Command + P + R all at once.
Keep holding all four keys for about 20 seconds.
- On older Intel Macs with a startup chime: hold until you hear the startup sound a second time.
- On newer Intel Macs without a chime: hold until the Apple logo appears and disappears twice.
Release the keys and let your Mac start up normally.

After restarting, go back to System Settings > Keyboard and re-check your function key toggle (Fix 1). NVRAM reset clears that setting back to default.

For more detail, see <a href=”https://support.apple.com/en-us/102439″ target=”_blank” rel=”noopener noreferrer”>Apple’s official NVRAM reset guide</a>.

Verification: Test your function keys after the Mac restarts and you’ve re-applied your keyboard settings.

Fix 7: Update macOS

A macOS update can reset keyboard settings or introduce a bug that affects function key behavior. Running the latest version is an easy way to rule out a known software bug. Apple does ship targeted keyboard fixes in point releases.

Click the Apple menu > System Settings (or System Preferences on Monterey or earlier).
Click General > Software Update.
If an update is available, click Update Now and follow the prompts.

After updating, check your keyboard settings to confirm the function key toggle is still set the way you want. Updates occasionally reset preferences.

If your function keys stopped working right after a macOS update: This is a known pattern. Check Apple’s support forums or the Apple Support page for keyboard issues to see if others are reporting the same bug. Sometimes the only fix is waiting for the next point release.

Fix 8: Check for Physical or Hardware Issues

If you’ve worked through every fix above and specific keys are still completely dead, the problem may be physical. Here’s how to rule out hardware damage systematically.

Step 1: Test in a New User Account

Software settings and third-party apps are tied to your user account. If the keys work fine in a fresh account, the problem lives in your account’s settings or an installed app, not in the hardware.

Go to System Settings > Users & Groups (or System Preferences > Users & Groups).
Click Add Account (you may need to unlock the panel with your <a href=”https://www.switchingtomac.com/macbook-password-not-working-8-ways-to-fix-right-now/”>password</a> first).
Create a new standard user account, log into it, and test your function keys.

If the keys work in the new account, go back to your main account and look harder at keyboard customization apps and accessibility settings.

Step 2: Clean Around the Keys

Dust, crumbs, and debris under keycaps can prevent keys from making proper contact. Use a can of compressed air held at an angle to blow debris out from around the affected keys. Apple recommends holding the MacBook at roughly a 75-degree angle and spraying in a left-to-right motion across the keyboard.

For more detailed cleaning steps, see <a href=”https://www.switchingtomac.com/how-to-clean-your-macbook-keyboard-the-right-way/”>Apple’s keyboard cleaning guidance</a>.

Step 3: Contact Apple Support

If the keys fail in the new user account and cleaning doesn’t help, you’re most likely looking at a hardware problem, either a failed key mechanism or a logic board issue. At that point:

Book a Genius Bar appointment at your nearest Apple Store.
Or contact Apple Support at support.apple.com to start a mail-in repair.
If your MacBook is under warranty or covered by AppleCare+, keyboard repairs are typically covered.

Good to know: Apple has run extended repair programs for keyboard issues on certain MacBook models in the past. Check Apple’s repair programs page before paying for anything, your model may qualify for a free repair.

Error Messages and Symptoms Reference

What You’re Seeing	What It Means	Fix to Try
F-keys dim/brighten screen instead of acting as F1, F2	Standard function key mode is off	Fix 1
Fn key opens Emoji picker instead of switching modes	Fn key behavior is set to “Show Emoji & Symbols”	Fix 2
F3 always opens Mission Control no matter what	macOS Mission Control shortcut is claiming F3	Fix 3
Function keys work on desktop but not in one specific app	App-level shortcut conflict	Fix 3
Keys work normally after quitting a background app	Third-party keyboard app was intercepting input	Fix 4
Keys only register if held down for a second or more	Slow Keys is enabled	Fix 5
All function keys stopped working after macOS update	NVRAM corruption or settings reset	Fix 6 or Fix 7
One or two keys are completely silent in all apps and accounts	Physical hardware failure	Fix 8

Platform-Specific Notes

Apple Silicon Macs (M1, M2, M3, M4, MacBook Air and MacBook Pro)

No NVRAM reset needed. Apple Silicon Macs handle memory management automatically. Skip Fix 6.
The Globe key (bottom-left corner of the keyboard) replaces the traditional Fn key on all Apple Silicon MacBooks. It toggles function key modes the same way, but it also handles language switching and emoji input.
All other fixes (1–5, 7–8) apply identically.

Intel Macs (MacBook Air and MacBook Pro models before late 2020)

Your key is labeled Fn, not Globe.
NVRAM reset (Fix 6) is available and worth trying if other fixes haven’t worked.
If you’re running macOS Monterey or earlier, keyboard settings are in System Preferences > Keyboard, not System Settings.

External Keyboards Connected to a MacBook

External keyboards, especially non-Apple ones, don’t automatically inherit your MacBook’s function key settings. If your <a href=”https://setapp.com/how-to/mac-function-keys” target=”_blank” rel=”noopener noreferrer”>external keyboard’s F-keys aren’t behaving as expected</a>:

Go to System Settings > Keyboard > Keyboard Shortcuts.
Also check Modifier Keys in the Keyboard settings panel, which lets you remap keys on a per-keyboard basis.
When you first connect a non-Apple keyboard, macOS may show a Keyboard Setup Assistant to help identify the layout. Complete this if prompted.

Prevention Tips

Check keyboard settings after every major macOS update. Updates occasionally reset the function key toggle back to default. A quick visit to System Settings > Keyboard after updating takes 10 seconds and prevents a lot of confusion.
Be selective with keyboard customization apps. Karabiner-Elements and similar tools are powerful, but every rule you add is another potential conflict. Review your rules periodically and remove ones you no longer use.
<a href=”https://www.switchingtomac.com/how-to-clean-your-macbook-keyboard-the-right-way/”>Keep your MacBook clean</a>. A blast of compressed air every few months stops debris from building up under the keys before it causes real problems.
Stay current on macOS updates. Apple regularly ships keyboard-related bug fixes in point releases. Staying updated is one of the lowest-effort things you can do to avoid issues.

Wrapping Up

The vast majority of function key problems trace back to two things: the <a href=”https://www.switchingtomac.com/10-macbook-pro-tips-for-beginners/”>standard function key toggle being off</a>, or a shortcut conflict with macOS or a third-party app. Fix 1 covers the first case and solves it for most people. Work down from there if you need to.

If you’ve been through all eight fixes and specific keys are still dead in every app and every user account, that’s hardware. Get Apple involved sooner rather than later. Keyboard repairs on in-warranty MacBooks are generally handled without much fuss.

Last updated: June 2026 | Applies to all MacBook models running macOS Monterey through macOS Sequoia