How to Compare Two PDFs for Free (No Upload, No Signup)
You've got two PDFs — maybe a revised contract from a client, or two versions of a report — and you need to know: what actually changed? Skimming page by page is slow, error-prone, and easy to miss subtle differences like a shifted margin, a changed number, or a repositioned logo. This guide shows how to compare two PDFs side by side and get a pixel-level difference report using en.sotool.top/compare-pdf . It's free, runs entirely in your browser, and your files never leave your device. Why comparing PDFs is harder than it looks On the surface, comparing two PDFs seems like comparing two text files. But PDF is a presentation format , not a content format. Two PDFs can be "identical" visually but have completely different internal structures: different fonts, different coordinate systems, different compression, different object ordering. That means text-based comparison tools often miss visual changes. A changed font size, a repositioned image, or a shifted table won...