Compare PDFs
Highlight changed areas and words between two versions.
Shows what changed between two versions of a PDF. Each page is drawn from both files and compared pixel by pixel: the areas that look different are outlined in red on a before-and-after pair of pictures. The text of each page is compared word by word, with removed words struck through and added words underlined. A summary lists the changed pages and any pages added or removed, and you can download the result as a text report.
How to use it
- Choose the two PDFs. The first is treated as the earlier version.
- Select Compare PDFs. Pages are compared one by one; long documents take a little while.
- Review the changed pages. Select Swap earlier and revised if the files were the wrong way round, and download
comparison.txtfor a record of the text changes, marked[-removed-]and{+added+}.
Options
| Option | Values | Default |
|---|---|---|
| Documents | Choose two or more files |
Limits
No file size or page limit. Everything runs on your device, so very large files are fastest on a computer. Pages are paired by position: page 1 with page 1, page 2 with page 2. If a page was inserted or deleted, every page after it is reported as changed. Text is compared as words, so changes to spacing or line breaks alone don’t count; when a page changed too much to compare word by word, whole lines are marked instead. Scanned pages have no text, so only their appearance is compared; run OCR PDF first to compare their words too. Pictures are shown for the first 60 changed pages; the summary and report cover every page. superPDF shows what changed but doesn’t explain it in words.
Scanned pages
Scanned pages, including copier scans whose text layer is weak or garbled, are read with the quick reader first (the AI tools run OCR PDF for you), so you get a result straight away. On computers that can run it, superPDF then offers high-accuracy reading beside the result, and improves those pages in the background: in Chat and Ask multiple PDFs the pages behind your latest question come first and new questions use the improved text; elsewhere, Run again with the improved text redoes the result. It runs on this device: nothing leaves it, and it works offline once downloaded. Download: 871 MB, once, only when you choose it; delete it any time in On-device AI models. Speed: about 10 to 30 seconds a page on a recent computer (the offer shows the time for your pages); up to 20 pages are read at a time unless you choose more or pick pages. It reads English and other European languages best; check results in other scripts, and like any OCR it can misread faded or handwritten text. Running page headers, footers and page numbers are left out of the text. If anything goes wrong, the quick result stays, with a short note. See High-accuracy reading.
Privacy
Runs in your browser. Your files are processed on your device and never uploaded.