Mac Function Keys (F1-F12) Doing the Wrong Thing? Use Them as Standard Function Keys

Pressing F1-F12 on your Mac adjusts brightness, volume, or Mission Control instead of doing what an app expects from a real function key.

Why: By default, the top row of an Apple keyboard controls Mac features (brightness, media, volume) rather than acting as F1-F12. That’s fine for everyday use, but apps and remote-desktop sessions that need true function keys behave oddly until you tell macOS to send F1-F12 instead.

Fix 1: Hold the Fn/Globe key for a one-off press

For an occasional function-key press, hold the Function (Fn)/Globe key while pressing the top-row key.

For example, Fn + F3 sends F3 to the app instead of opening Mission Control. This is the quickest option when you only need a standard function key now and then and want to keep the brightness/volume controls the rest of the time.

Fix 2: Make F1-F12 standard function keys permanently

If you always want the top row to act as F1-F12 (so you press the Fn key only when you want brightness/volume):

1. Open the Apple menu > System Settings, then click Keyboard in the sidebar.
2. Click the Keyboard Shortcuts button on the right.
3. Click Function Keys in the sidebar.
4. Turn on Use F1, F2, etc. keys as standard function keys.

Now pressing F1-F12 sends the plain function key, and holding Fn gives you brightness, volume, and the other built-in features instead.

FAQ

My MacBook Pro has a Touch Bar instead of physical keys. Press and hold the Fn (Function) key to show F1 through F12 in the Touch Bar, then tap the one you need.

A third-party keyboard ignores this setting. Some non-Apple keyboards need the maker’s own utility to change function-key behavior, and behavior can also vary per app. Check the manufacturer’s software if the System Settings option doesn’t take effect.

Sources: Apple Support — How to use the function keys on your Mac