Compare two PDFs
Compare two versions of a PDF side by side. Changed words are marked on the pages, every change is listed, and a pixel comparison catches changes in scans and pictures. Download a report. Runs in your browser, so nothing is uploaded.
Runs in your browser — this file is never uploaded
How to compare two PDFs
- 1
Add both versions
Drop the original into the left box and the revised version into the right one. Both stay on your device.
- 2
Look through the changes
The pages appear side by side with the differences marked: red for words only in the original, green for words only in the revision. Every change is listed underneath; click one to jump to it. Switch to Visual to compare the pages pixel by pixel.
- 3
Download the report
Get a PDF that lists every change and shows each differing pair of pages side by side, marked up — ready to send to whoever needs to see it.
Frequently asked
What kinds of changes does it find?+
Every word that was added, removed or changed, wherever it moved to. The two documents are compared as a whole, so a paragraph added on page 2 that pushes the rest of the text down shows as one change, not as every later page being different. The Visual view compares pixels instead, so it catches changes to pictures, layout and scanned pages that have no text.
Do the pages have to line up?+
Pages are shown side by side in order — page 3 next to page 3. If one version has more pages, the extra ones are shown on their own. The text comparison does not depend on the pairing, so moved text is still found.
Does it work on scanned documents?+
The text comparison needs text, so run scans through OCR PDF first. The Visual view works on anything, scans included.
What is in the report?+
A summary page listing every change with the words before and after, then each pair of pages that differ, side by side with the changes marked in red and green.
Is Compare PDFs free to use?+
Yes. Compare PDFs is free and unlimited, with no account and no watermark added to your document.
Are my files uploaded to a server?+
No. Compare PDFs runs entirely inside your browser, so the document never leaves your device.
Which browsers does it work in?+
Any current version of Chrome, Edge, Firefox or Safari, on desktop, tablet and phone.