diff-pdf is a tool for visually comparing two PDFs. It takes two PDF files as arguments. By default, its only output is its return code, which is 0 if there are no differences and 1 if the two PDFs differ. If given the --output-diff option, diff-pdf produces a PDF file with visually highlighted differences: $ diff-pdf --output-diff=diff.pdf a.pdf b.pdf Another option is to compare the two files vi
![diff-pdf](https://cdn-ak-scissors.b.st-hatena.com/image/square/24191d71ca06b01167c5190f4e1536fa2313db5e/height=288;version=1;width=512/http%3A%2F%2Fvslavik.github.io%2Fdiff-pdf%2Fscreenshot.png)