How to compare two PDFs
- Add the original PDF in the first box, and the changed version in the second (or drop both at once: the older file is taken as the original).
- Tap "Compare the two PDFs".
- Go through the changes in the list: each shows the words removed and added, with both pages side by side and the change boxed.
- Download the changed PDF with the changes marked, to keep or send.
Good to know
The words of both PDFs are compared line by line, then word by word, as a person reads them. Text that only moved to another line or page, because a margin or a paragraph above changed, doesn’t count as a change.
In the marked copy, added words are highlighted in green, changed words in blue with the old words in their note, and each removal has a note with the words that were removed. They are standard PDF comments, so Adobe Acrobat and other PDF apps show them.
Only the words are compared, not pictures, colors or layout. A scanned PDF is a picture of each page, so it has no words to compare.
Comparing the first 5 pages of each PDF is free. Plus and Enterprise compare whole PDFs.
Questions
Can it compare Word documents?
Save both versions as PDF first (in Word, choose File, then Save as or Export, and pick PDF), then compare the two PDFs.
Does it compare scanned PDFs?
A scan is a picture of each page, so it has no words to compare. The tool says so.
Are my files uploaded?
No. Both PDFs are read and compared by your browser on your device.
Page last reviewed 26 October 2026.