Compare PDFs

Compare PDFs shows you what is different between an older and a newer version of a document: a contract that came back from the other side, a revised quote, a policy update, a student’s second draft. Add both files and the tool reads the text of every page, lines the two versions up word by word, and lists each change as added, removed or changed, with the pages it sits on.

You can look at the changes three ways. Side by side shows both pages with removed words marked in red on the old page and added words in green on the new one. Text shows the new document in reading order with deletions struck through and additions underlined, long unchanged passages folded away. Overlay lays the two pages on top of each other and highlights every pixel that differs, which catches changes in pictures, signatures, layout and scanned pages that have no text at all.

Prev and Next step through the changes in every view, and the change report downloads as an HTML page or plain text for your records. Both files stay on your device the whole time.

1. Choose the earlier version under “Original (older)” and the later one under “Changed (newer)”. Tap the swap button if you put them the wrong way round.
2. Read the totals: number of changes, words added and removed, and pages. Tick “Ignore capital letters”, “Ignore punctuation” or “Ignore spacing” to hide changes you don’t care about.
3. Use “Side by side”, “Text” or “Overlay”, and step through the changes with Prev and Next or by tapping one in the Changes list.
4. Press “Download report (HTML)”, or “Download as plain text”, to keep a list of every change.

• Word-by-word comparison of the whole document, so text that moves onto another page doesn’t show as a change.
• Handles files with different page counts: added and removed pages appear as changes.
• Side-by-side pages with removed words in red and added words in green, and a marker where text was inserted or taken out.
• Text view with deletions and additions in place, folded unchanged passages and page markers.
• Pixel overlay for any pair of pages, with highlight or fade modes; works on scanned PDFs.
• Options to ignore capital letters, punctuation and spacing differences.
• Change list with page numbers, plus Prev and Next to jump between changes in every view.
• Downloadable report as a self-contained HTML page or plain text.

• Scanned PDFs have no text to read, so words can’t be compared; the tool says so and opens Overlay, which compares how the pages look. Run PDF OCR on both scans first to compare their words too.
• For contracts, leave every “Ignore” box off: a changed comma or capital can change the meaning.
• Overlay compares the page you pick on each side, so a page that moved (say page 4 became page 5) can still be checked by choosing those two pages.
• Text that only changed style (bold, colour, font) has the same words, so it won’t appear in the list. Overlay will show it.
• The HTML report opens in any browser and prints neatly, which makes it easy to attach to an email.