Set up hot corners on a Mac without triggering them by accident
· 5 min read
Hot corners are set in System Settings, Desktop & Dock, under the Hot Corners button at the bottom of the pane. The fix for accidental triggers is in the same panel and almost nobody finds it: hold a modifier key (Command, Option, Shift or Control) while you choose an action from a corner’s menu, and that corner will only fire when the same key is held. A corner that needs Option plus a flick of the wrist is never triggered by reaching for the Apple menu.
Set a corner up
- Open System Settings, click Desktop & Dock, and scroll to the bottom.
- Click Hot Corners.
- The panel shows a preview of the screen with a menu at each corner. Click the menu for the corner you want.
- Before you pick the action, hold down a modifier key. The menu items gain the key’s symbol next to them.
- With the key still held, choose the action. The corner’s menu now shows the symbol beside the action name.
- Click Done.
Test it. Push the pointer into that corner with nothing held: nothing happens. Hold the key and do the same: the action fires. If you skipped the modifier, the corner fires on every touch, which is the default behavior and the reason the feature has a reputation.
A modifier is a per-corner choice. You can leave one corner bare for something harmless and require a key on the corner that locks the screen.
The corner to fix first
On a new Mac, the bottom-right corner is already set to Quick Note. That is the corner the pointer drifts into when you reach for the Dock’s right end or the Trash, so a Notes window slides in from the edge several times a day. If you have wondered why a note keeps appearing, this is why.
Open the Hot Corners panel and either set that corner to the dash (no action) or add a modifier to it. Quick Note is useful on a Mac where you actually use Notes; the accident is having it bare.
Which actions are worth a corner
The menu offers a fixed list. The ones that earn a corner:
Lock Screen. The best use of a corner on a laptop that leaves the house. Flick, and the Mac locks. Pair it with an immediate password requirement, covered in Require a password immediately after a Mac sleeps, and standing up from the desk becomes a security habit that costs nothing. Give this corner a modifier; locking by accident mid-sentence is irritating, and Control-Command-Q exists for when you want it deliberately.
Put Display to Sleep. Same idea, screen off instead of locked. With an immediate password requirement, the two are equivalent.
Desktop. Pushes every window aside to show the Desktop, and pulls them back when you leave the corner. Handy on a Mac where things get dragged onto the Desktop often. On Sonoma and later, clicking the wallpaper does something similar, so this corner matters less than it did.
Mission Control. Shows every open window. Useful if you do not use the trackpad gesture or the F3 key for it.
Disable Screen Saver. The odd one out: while the pointer sits in this corner, the screen saver and display sleep are held off. Useful when something needs to stay visible and you would rather not change the display timeout.
Application Windows, Notification Center and the screen saver are on the list too and have their fans. The advice is the same as in The Mac settings worth changing in the first ten minutes: start with one corner, live with it for a week, and add a second only if you find yourself wanting it.
Corners and external displays
Hot corners apply to the corners of the whole desktop, which with two displays side by side means the outer four corners. The corners where the two screens meet are not corners as far as macOS is concerned, because the pointer passes straight through. A corner action on the right of the left display will not fire; the one on the far right of the right display will.
Moving from a single-screen setup to a docked one is where corners start firing unexpectedly, because the geometry changed and your hand did not. Adding a modifier to each corner removes the problem in both setups, which is a better answer than remembering to reconfigure.
Turning the whole thing off, and back on
Set each corner to the dash in the menu. There is no master switch. If you want corners in one situation and not another (a presentation on a projector, for instance, where a stray Mission Control is the last thing you want), Mainspring has a “hot corners” power-up that can be part of a scene, so the corners go off when a display connects and come back when you unplug. macOS itself has no way to tie hot corners to a display or a time.
Questions
Can I make a corner wait a moment before it fires? No. macOS triggers on contact with the corner pixel, with no delay setting. The modifier key is the only built-in guard.
Why does my corner work with the trackpad but not the mouse? It works with both, but a mouse at a high tracking speed tends to overshoot into the corner, while a trackpad stops where your finger stops. If a mouse corner fires too often, add a modifier rather than lowering the speed.
Is there a way to see which corners are set without opening the panel? Not in macOS. The Hot Corners panel is the only place the assignments are shown.
Does a hot corner work when an app is full screen? Yes. Full-screen apps hide the menu bar and Dock, but the corners still respond, which is one reason to keep the lock-screen corner behind a modifier: a video playing full screen is exactly when a stray pointer finds the corner.