Compare PDF Files
See exactly what changed between two versions of a PDF — every added, removed, changed or moved word is highlighted on the pages side by side, with a visual mode for scans and layout changes. Free, and nothing is uploaded.
Free · No sign-upHow to use Compare PDF
- 1. Drop the original PDF into box A and the changed version into box B (or drop both files at once).
- 2. The Text changes list shows every difference with page numbers: removed words in red, added in green, moved blocks in blue. Click one to jump to it on both pages.
- 3. Tick Ignore case, Ignore punctuation or Ignore spacing & line breaks to hide changes you don’t care about.
- 4. For scans, images or layout changes, switch to Visual compare. Click Export report to save an HTML report with the highlighted pages.
Frequently asked questions
Are my PDFs uploaded?
No. Both files are read with pdf.js and compared in your browser, and the report is generated on your device. Nothing is sent to a server.
How does the text comparison work?
The tool extracts the words of each PDF with their positions, lines the two documents up line by line, and then compares word by word inside every changed passage (the Myers diff algorithm). Text that only reflowed to another line isn't reported, and each change is highlighted on the rendered pages and listed with its page numbers.
Can it detect moved text or pages?
Yes. When a block of at least six words is removed in one place and shows up elsewhere unchanged or almost unchanged (at most one word in ten different), it is reported once as Moved, in blue, instead of as a deletion plus an addition.
Can I compare scanned PDFs?
Scans have no text layer, so use Visual compare: it renders both pages and paints pixels that exist only in A red and only in B green, with boxes around changed areas. If neither file has text, the tool switches to visual mode automatically.
What doesn't the text comparison catch?
Formatting-only changes such as font, color or size, and changes inside images, are not text differences — Visual compare shows those. Highlight boxes are placed from the PDF's text positions, so they can be slightly off for unusual fonts or vertical text.
What is in the exported report?
A single HTML file you can open in any browser or print to PDF: file names, the options used, summary counts, the full list of changes, and images of the first 30 changed page pairs with the differences highlighted.