Over deze extensie
Open panel to left, bottom or right (left,middle or right click) with current URL from Split on context menu (right click on page) of the tab's page. And Ctrl-click or Shift-click on menu item for same as middle or right click. Double-click on panel title bar to open location prompt. Allows you to view see two pages simultaneously for comparison or copying info from one to the other. Can be resized by dragging the bar between the main browser and new panel.