The Accidental Emoji Menu
On modern Mac keyboards, the ‘fn’ (Function) key in the bottom left corner is often mapped by default to summon the macOS Character Viewer—a floating window containing emojis, symbols, and special characters. While this provides quick access to emojis during casual chats, it is highly problematic for users who frequently use keyboard shortcuts. If your palm grazes the fn key, or if you hesitate for a split second while pressing a complex shortcut like fn+Up Arrow (Page Up), the Character Viewer will unexpectedly pop up on your screen, stealing focus from your active application and interrupting your typing flow.
Reassigning the Function Key
To stop this annoying popup, you need to change the behavior of the fn key in the System Settings, instructing macOS to either do nothing when it is pressed alone, or to perform a less intrusive action like changing the input source.
Open the System Settings app by clicking the Apple logo in the top left corner of your screen. Scroll down the left-hand sidebar and select Keyboard. In the main pane on the right, locate the section labelled “Keyboard navigation.” Look for the dropdown menu titled Press fn key to (or “Press globe key to” on newer models). Click this dropdown menu. By default, it is likely set to “Show Emoji & Symbols.” Change this selection to Do Nothing. The change is immediate. You can now rest your hand near the fn key or use it for complex shortcuts without the Character Viewer suddenly appearing on your screen.