Viewport Dimensions is a Chrome extension that displays the current dimensions of the viewport and window when the browser window is resized. This is helpful if you need to test out the layout of a website or if you’re creating a video recording of your screen and want to ensure that it will be at the correct resolution. 

It is useful to know the current resolution of your screen so you can record the best quality video and make the best quality video recordings. 

You can adjust the size of the viewport and window to your preference. It is recommended to set it to the recommended settings, or to the maximum settings if you are using a large monitor.