Compare PDF
Spot the differences between two PDFs, side by side.
Open Compare PDF →What is Compare PDF?
A free, private tool that spots the differences between two PDFs side by side. It extracts the text from each file and shows what was added, removed or kept, all in your browser — nothing is uploaded. It works best on text-based PDFs rather than scanned images.
How to use Compare PDF
- Load both PDFs — Drop the original into slot A and the revised version into slot B, or click each slot to choose a file.
- See the summary — Once both are loaded, the toolbar tallies how many parts were added, removed and left unchanged.
- Choose a view — Switch between Side by side, Unified diff and Changes only to read the differences whichever way suits the document.
- Review and reset — Scan the highlighted changes, then use Reset to clear the files and compare another pair.
Frequently asked questions
Are my PDFs uploaded to compare them?
No. The text is extracted and compared entirely in your browser, so both files stay on your device and the tool works offline after the first load.
Does it work on scanned PDFs?
It works best on text-based PDFs. Scanned pages are images with no extractable text, so there is nothing for the comparison to read.
What do the three views show?
Side by side places the two documents in parallel columns, Unified diff merges them into one marked-up stream, and Changes only hides the unchanged text so you see just what differs.
What counts as added, removed or unchanged?
Text that appears only in B is added, text only in A is removed, and text in both is unchanged — the toolbar shows a count for each.
Tips
- Put the older file in slot A and the newer one in slot B so additions and removals read the right way round.
- Use Changes only on long documents to jump straight to what differs.
- If a PDF shows no text, it is probably a scan — run it through OCR first.