How to use Compare PDF
- Select the original PDF (A) and the new version (B).
- Click “Compare PDFs”.
- Read the list of text changes and download the visual report.
Two kinds of comparison
Text: lines are compared in order and shown as added (+) or removed (−), with unchanged neighbouring lines for context. Visual: each page of B is overlaid on A; content that is new appears green and content that disappeared appears red in a downloadable report PDF.
The visual comparison works best when both files have the same page size and layout. Scanned files can only be compared visually.
🔒 Your files never leave your device
bopdf processes your documents locally with JavaScript (pdf-lib and Mozilla pdf.js) inside your browser tab. Your PDF is never uploaded, stored or seen by us — you can even disconnect from the internet after the page loads and the tool keeps working. When you close the tab, everything is gone.
Frequently asked questions
Are both files kept private?
Yes, both are compared in your browser.
Can it compare Word files?
Convert them to PDF first with Word to PDF.
Are my files uploaded to a server?
No. Everything happens in your browser on your own device. Files are never sent over the internet, which makes bopdf suitable for confidential documents.
Is there a file size limit?
There is no fixed limit, but very large files (hundreds of MB) depend on your device memory. On phones, files up to about 100 MB usually work well.