How to compare two versions of a PDF
Compare PDF puts two documents, the original and the new version, against each other and produces a PDF report showing both versions side by side for every page. Areas that changed visually are highlighted in pink on the new version, and underneath you get the words that were added, removed or replaced.
Use it to review a contract that comes back from the other party, see what changed in a quote or a drawing, or make sure a corrected design did not alter anything else.
Step by step
- Upload exactly two PDFs: the original first, then the new version.
- Check the order in the file list; you can move each file up or down.
- Process and download the comparison report.
- Go through the report page by page and confirm each change in the real document.
Two comparisons in one
The visual comparison overlays the pages and marks any pixel difference in pink: a changed figure, a moved logo, a new table or a colour change. It also catches changes that are not text, such as signatures, stamps or images.
The text comparison extracts the words on each page and lists the differences. It only works when the PDFs contain real text; scans have no text to compare, although the visual comparison still works. You can run scans through OCR PDF first.
Reading the result
Pages are paired by position: page 3 of the original with page 3 of the new version. If a page was inserted or removed, every following page will be shifted and full of differences. In that case, match the page count first with Remove pages or Extract pages, then compare again.
Each page's list of text changes is condensed to a single line, so pages with many edits will not show them all. Treat it as a pointer and rely on the visual highlighting. Each PDF can have up to 50 pages and the whole job up to 50 MB.
Frequently asked questions
- How many PDFs can I compare?
- Exactly two: the original and the new version.
- How are the differences shown?
- In a PDF with both versions side by side; visual changes are highlighted in pink and text changes are listed at the foot of each page.
- Does it work with scanned PDFs?
- The visual comparison does. The text comparison needs real text, so apply OCR first if you want to compare words.
- What if one version has an extra page?
- Pages are compared by position, so everything after that page will look shifted. Match the pages first.
- Does it replace a legal review of a contract?
- No. It helps you find changes, but read the final document before you sign it.