Whether you're checking a revised contract against the original, comparing two drafts of a report, or verifying that a re-exported PDF matches the source, eyeballing two documents page by page is slow and error-prone. This tool renders both files side by side and flags which pages have different text content, so you know exactly where to look.
The comparison runs entirely in your browser: both PDFs are parsed using Mozilla's pdf.js library, page thumbnails are rendered for visual inspection, and the text layer of each page is compared to determine a match or a difference. Because nothing is uploaded, this works even for confidential or unreleased documents.
For a page-count mismatch (say, one PDF has an extra appendix page), the tool will flag it and continue aligning the remaining pages by number — worth double-checking manually if pages were inserted in the middle rather than at the end.