macOS includes a window management feature called “Hot Corners.” By design, this feature allows you to trigger specific system actions (like launching Mission Control, showing the Desktop, or putting the display to sleep) simply by shoving your mouse pointer into one of the four extreme corners of your screen.
While this can be a powerful shortcut for some, it is often a catastrophic annoyance for others. If you are playing a fullscreen video game, attempting to click the Apple logo in the top-left corner, or trying to access the Notification Centre in the top-right corner, a slight overshoot of your mouse will instantly trigger the Hot Corner. Suddenly, all your windows fly off the screen, or your display instantly goes black, completely breaking your workflow. If you constantly trigger these actions by accident and prefer to rely on keyboard shortcuts for window management, you must completely disable all Hot Corners.
Disabling Hot Corners via Desktop & Dock Settings
You can individually castrate each of the four corners directly from the modern macOS System Settings menu.
- Click the Apple Logo in the top-left corner of your Mac’s screen and select System Settings….
- Scroll down the left-hand navigation sidebar and click on Desktop & Dock.
- Scroll to the absolute bottom of the main panel on the right side.
- Click the button labelled Hot Corners… located in the bottom right corner.
- A small popup window will appear displaying a graphic of your monitor, with four dropdown menus corresponding to each corner.
- Click on the first dropdown menu that has an action assigned to it.
- Scroll to the absolute bottom of the list and select the blank dash symbol ( — ).
- Repeat this process for all four dropdown menus until every single corner displays the blank dash symbol.
- Click the Done button to save your changes.
The change takes effect instantly. You can now aggressively throw your mouse pointer into any corner of the screen without fear. Your display will remain perfectly static, ensuring that Mission Control or the screen saver will only launch when you explicitly command them to via a keyboard shortcut or trackpad gesture.