Compare PDF — Find Differences Between Two Documents
Upload an original and a modified PDF to see exactly what changed. Differences are highlighted page by page, with a change percentage and three viewing modes. Everything runs in your browser.
Key Features
Visual Difference Highlighting
Changed areas are highlighted in red and page-size differences in blue, so you can spot every change at a glance.
Three View Modes
Compare side by side, blend two pages in an overlay with adjustable opacity, or view the pure difference image.
Change Percentage
Every page reports the exact percentage of changed pixels, plus a quick summary of how many pages differ.
Page Navigation
Jump between pages with next/previous controls and a thumbnail overview that marks identical and changed pages.
100% Private
All processing happens locally in your browser. Your files are never uploaded to any server.
No Install, Free
Works on any device with a browser. No sign-up, no watermarks, and completely free.
What Is PDF Comparison?
PDF comparison finds the differences between two versions of a document. Instead of reading both files side by side, the tool renders each page of the two PDFs and compares them pixel by pixel, highlighting every changed area. This is especially useful for checking edits in contracts, reports, or designs, verifying that only the intended changes were made, and reviewing revisions before sharing. Differences in text, images, layout, and page size are all visible at a glance. All processing happens locally in your browser, so your documents stay private.
How to Compare Two PDFs
Comparing PDFs takes just a few steps. Everything runs in your browser.
Upload the two PDFs
Add the original PDF in the first slot and the modified PDF in the second. You can drag and drop or click to browse.
Choose a page range (optional)
To compare only some pages, enter a range such as 1-3, 5. Leave it empty to compare all pages.
Compare the documents
Click Compare PDFs. Each selected page is analyzed and the differences are highlighted.
Explore the differences
Use the side-by-side, overlay, or difference view, and navigate pages to review every change and its percentage.
Good to Know
Comparison is pixel-based, so formatting differences such as font rendering, spacing, or anti-aliasing may register as small changes. Pages present in only one document are reported as 100% different. Very large documents take longer to compare; use a page range to limit the work. Password-protected PDFs must be unlocked before comparing.