If you work with lots of PDF documents, you may need to compare two versions of the same PDF. While Acrobat Professional provides this feature, another product focuses exclusively on making comparisons easier for you: PDF Comparator Professional, from Premedia Systems.

Now in its third generation, it comes in a $125 “Standard” version and a $195 “Professional” version. They claim it’s better than Acrobat in some ways, including ease of use, clarity of differences, greater control of comparison parameters (including some that Acrobat misses), and it’s faster.

Our favorite feature is the ability to open three windows to view a pair of pages, with or without synchronized sizing, zooming, and scrolling — one window for each document, and a third to display their differences.

Jay Nelson

Jay Nelson is the editorial director of PlanetQuark.com, and the editor and publisher of Design Tools Monthly. He’s also the author of the QuarkXPress 8 and QuarkXPress 7 training titles at Lynda.com, as well as the training videos Quark includes in the box with QuarkXPress 7 . In addition, Jay writes regularly for Macworld and Photoshop User magazines and speaks at industry events.