In Ubuntu (GNOME desktop), the top-left corner of your screen is an active “Hot Corner.” If you rapidly flick your mouse cursor into the extreme top-left pixel of your monitor, Ubuntu instantly triggers the “Activities Overview,” zooming out all your windows and pulling up the application launcher.
While designed for speed, this feature is highly problematic for users with multi-monitor setups, or for gamers playing full-screen strategy games where the mouse constantly hits the edges of the screen. Accidentally triggering the Hot Corner violently rips you out of your workflow. You can easily disable this invisible trigger zone.
How to Turn Off the Top-Left Hot Corner in Ubuntu
You can disable the Hot Corner directly from the Ubuntu Multitasking settings menu.
- Click the network/battery icon cluster in the top-right corner of the Ubuntu top bar and select Settings (the gear icon).
- In the left-hand navigation sidebar, scroll down and click on Multitasking.
- Look for the section titled General at the top of the page.
- Locate the toggle switch labelled Hot Corner (with the description “Touch the top-left corner to open the Activities Overview”).
- Click the toggle switch to turn it Off.
The change is instantaneous. Try slamming your mouse cursor into the top-left corner of your screen—absolutely nothing will happen. You can now use the edges of your screen aggressively without accidentally triggering the GNOME Activities Overview.