There are a lot of questions up here about comparing two PDF files, but I have (what I think is) a different requirement.
We generate documents that are structured around outlines - section 1, section 1.1, etc. The problem comes when we insert a new section early in the document. You can imagine, this not only increases all of the section numbers, but also increases the page count, so there are a lot of changes that, while real, are not terribly interesting.
But the big problem is that every tool I've tried (including Adobe Acrobat Pro DC) has real problems if an inserted section bumps text onto a new page. They seem to have a real problem noticing that the exact same text appears on page 5 of the old document, and page 6 of the new document.
We're happy to pay for such a tool, but we need a PDF comparison tool that can handle insertions early in a document that move subsequent text onto new pages.
We run both Macs & PCs so either one is fine. And if the software we need only runs on Linux, we would find a way!