Compare PDF Files Online Free
View two versions of a PDF document side by side and spot the differences. Free, no signup, files never leave your browser.
🔒 Your files never leave your browser. All processing is done locally.
Original PDF
Revised PDF
How to Compare PDF Files
- 1
Upload two PDF files
Click "Original PDF" to upload the first version and "Revised PDF" for the second. Both files are loaded in your browser.
- 2
Click Compare
Click "Compare PDFs". The tool renders all pages of both documents as image previews.
- 3
Review differences side by side
Scroll through the page pairs. Original pages appear on the left, revised pages on the right. Zoom in on any page pair to inspect details.
Comparing two versions of a PDF is a common task when reviewing contracts, proofreading documents, or checking that a revised report matches expectations. This tool renders both PDFs in your browser and displays them side by side, page by page, so you can scroll through and spot differences visually.
How rendering works: The tool uses pdfjs-dist(the same engine that powers Firefox's built-in PDF viewer) to convert each page to a canvas image. Both PDFs are processed entirely in your browser — your files never leave your device.
Zooming in: Click any page thumbnail in the comparison view to open a larger version in a lightbox. This makes it easy to inspect fine text changes, signature positions, or image differences.
Different page counts: If one PDF has fewer pages, blank placeholders appear in the comparison so the page numbering stays aligned across both documents.