How was it done? Interactive "Before and After" photo with slider
I saw this interactive graphic on a US government website (FDA). It shows a "before and after" version of an edited photo (picture of a retail counter, with "old" and "new" signage). The reader uses a little slider control that appears in the middle of the photo, and slides from one side to the other to see the "before" and "after" version. The slider button can also be controlled by keyboard letters (A and D), which nudge the button left or right.
Can anyone explain how this was done? Is there a template for this?
Here is the website where it appeared....
Many thanks as usual to this well-informed group!