Reply To: Compare PDF files

When I want to do a purely visual comparison, I usually do it by having both versions open at the exact scale and superimposed, then toggling them back and forth. The eye sees even tiny differences as movement, so they are very easy to spot.

For a single or double-sided piece, opening both versions as layers in Photoshop, one below the other, is a slightly roundabout but very precise way to do this, since you can just drag the opacity slider on the top layer back and forth or use the “Difference” blend mode. It's all but impossible to miss a change, even things as subtle as minor letterspacing differences in body copy.