What it does. Compares two PDF files and shows what changed. See added and removed words, red areas that differ on each page, or both pages side by side.
How to compare two PDFs
- Drop both PDFs onto the box, or choose File A and File B one by one.
- Press Compare PDFs.
- Read the summary, then switch between Text changes, Visual changes and Side by side.
- Download the visual comparison as a PDF if you want to share it.
Tips for better results
- Put the older file in A and the newer one in B, so additions show in green and removals in red.
- Use Next change to jump from one changed page to the next.
- If a page looks changed but the text is the same, check Visual changes for layout or image edits.
Limits to know about
- Text comparison needs PDFs with real text. For scans, use Visual changes.
- A small shift of the whole page can mark many areas as different.
- Very long documents take a while because every page is drawn and checked.
- Tested with generated sample PDFs. Check the result on your own file.
Privacy
Your file never leaves your device. It is processed inside your browser, and nothing is uploaded to our servers. The PDF libraries load from a public code network (cdnjs).
Frequently asked questions
Is Compare PDF free?
Yes, with no sign-up and no limit.
Can it compare PDFs of different lengths?
Yes. Extra pages are marked as only in File A or only in File B.
Does it compare scanned PDFs?
The visual view works on scans. The text view needs selectable text.
What do the red areas mean?
They are places where the two pages look different after both are drawn at the same size.
Are my files uploaded anywhere?
No. Both files stay in your browser.
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About this tool: free, no sign-up, works on phone and desktop. Last reviewed: November 2026.