Choose "Record a section" from the plus button beside Record, or turn on "Record only part of it" in any recording form. This needs Chrome or Edge.
- Pick the tab, window or screen in the browser's dialog as usual.
- A preview of what you shared appears with a box already drawn over the middle of it.
- Drag across the preview to draw a new box. Drag the box to move it. Drag a corner to resize it.
- Press "Start recording". Everything outside the box is left out.
With the keyboard
When the box has focus, the arrow keys move it, Shift with the arrow keys resizes it, and Escape clears it.
While recording
The tray shows the size of the area you chose, as "Area" followed by its width and height. The area is fixed for the take. To change it, press "Start over" and draw it again.
If the option is missing
In a browser that cannot do this, the form says "Selecting an area needs Chrome or Edge." Record the whole tab instead and trim the result, or switch browser.