In Ubuntu (which uses a customized GNOME desktop environment), thrusting your mouse cursor forcefully into the top-left corner of the screen triggers the “Activities Overview.” This zooms out your current windows and displays all your open workspaces and applications.
While this “Hot Corner” feature is designed for fast multitasking, it is notoriously frustrating for users with multi-monitor setups or gamers. If you accidentally flick your mouse slightly too far to the top-left while trying to click a browser tab or an in-game menu, your entire screen abruptly shifts into the overview mode. You can completely disable this top-left trigger.
How to Turn Off the Top-Left Hot Corner in Ubuntu
You can disable the Activities Hot Corner directly from the Ubuntu Multitasking settings.
- 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.
- In the main window on the right, look at the very top section labelled “General.”
- You will see a setting named Hot Corner with the description “Open the Activities Overview when the cursor goes into the top-left corner.”
- Click the toggle switch next to this setting to turn it Off.
The change is instantaneous. You can test it by throwing your mouse cursor into the top-left corner as hard as you can; the screen will not move. To access the Activities Overview moving forward, you must intentionally press the Super (Windows) key on your keyboard or click the “Activities” button on the top bar.