How can I zoom within Inspect?

To zoom while using Inspect, navigate to the top of the page and click the magnifying glass icon (). With this tool selected, click your screen to zoom in. To zoom out, hold Option + click (Alt + click for Windows).

You can also zoom using the + and - icons at the top right of the Inspect page. 

Pressing the escape key will deactivate the tool and bring you back to the selector tool.