How to take a screenshot of an entire web page on Mac. 4) With your webpage on the left, you can choose to view it as a different device at the top or just leave as Responsive. Screenshots: Press Cmd+Shift+3 to capture your entire screen, Cmd+Shift+4 to select an area to capture, or Cmd+Shift+5 to bring up a capture menu, where you can also choose screenshots … Press shortcut keys CTRL + A, this selects the entire data set as long as data cells have no blank rows in between. Press with left mouse button on 'Insert' on the top menu, see image above.