Compare PDFs

See exactly what changed between two versions.

Document A

Select the original

Click to choose, or drop a file here

Document B

Select the revised version

Click to choose, or drop a file here

How to Compare PDFs

1
Open the tool
Open the Compare PDFs tool and drop your file onto the page, or click to browse for it. Everything runs in your browser — the file is never uploaded.
2
Add both versions
Drop the original PDF and the changed PDF into their two slots.
3
Review the differences
The tool highlights what changed between the two versions, page by page.

Related PDF tools

Merge PDFCombine PDFs — plus images, Word, Excel and PowerPoint — in the order you want.Split PDFBreak a PDF into separate files by page range, or into equal chunks.Remove pagesDelete specific pages from a PDF.Extract pagesPull selected pages into a new PDF.

Compare PDFs — frequently asked questions

How is the difference percentage calculated?+

Each matching page pair is rendered as an image, and we count the percentage of pixels whose color differs beyond a small threshold — small enough to ignore anti-aliasing noise but sensitive to real content changes.

What if the two PDFs have a different number of pages?+

Pages that only exist in one document are flagged as 'Only in Document A' or 'Only in Document B' rather than compared against nothing.

Do you upload my files to a server?+

No — every tool here processes your files entirely on your device, and nothing is uploaded to a server. The AI tools that used to send extracted text to a server are currently disabled.

Is there a file size limit?+

There's no artificial limit we impose, but since processing happens in your browser, very large files (500+ MB or 1,000+ pages) are limited by your device's memory rather than by us.