DiffPDF is a lightweight open source tool which compares two PDF files and then shows the differences between them. It compares the words on each pair of pages and also supports the comparison character by character for logographic languages. It also supports the idea of comparing the pages by appearance. This means if a font or diagram is changed and a paragraph is reformatted, you can confirm if the documents are different or not by clicking the Log tab. You can also scroll through a PDF to visually check that everything is as you expected. The program also comes with an option to save a PDF with only the pages which vary, again with the differences highlighted. This comes in handy if you are running the comparison for someone else. You can even run DiffPDF from the command line; this is very useful if you are comparing a lot of files and need to automate the process to save time.
DiffPDF for Mac is a program designed to help with the comparisons of the words in your documents. The program allows you to run the comparison by characters, or even just appearance. Running the program by appearance is best suited for diagrams and reformatted paragraphs. It can also be used to compare particular pages or page ranges. DiffPDF is extremely easy to use. When you click “File #1” and specify your first file; click “File #2″ for the second,” then click “Compare” and within a second or two, your documents will be highlighted to show any differences between them.
The program comes with few more settings and features which might help if you run into problems. You can choose to exclude the margins and compare particular page ranges only within a PDF. The program also has a Zoning feature which is an interesting technique to try and avoid false positives. The latest version enables you to save a PDF file that shows the pages that differ with their differences highlighted. The program now offers full support for French and German translation, margin exclusion and improved dock window handling.