Compare two PDF documents - fast, incredibly easy and reliable!

What exactly has changed, what is really the same? How often do you get back a document and are still uncertain about the changes? Why is it such a hard task to juggle with revisions edited by many authors? If you just want to *see* what happened, then PDiff Express is made for you!

PDiff Express allows you to compare the content of two PDFs in order to pinpoint all textual changes. Just drag and drop two versions into PDiff and you will see all differences at a glance. This still works if fonts, layout, hyphenation or even page breaks were altered.

PDiff Express is an ideal solution to compare versions of your
• important office documents
• mission critical technical manuals
• legal texts and business contracts
• financial reports
• manuscripts and thesis texts
• scientific articles, reports, and proceedings
• fictional books and non-fiction books
• copywriting to ready-to-print layout

• free version compares PDF files with up to 3 pages (max. 1000 words)
• in-app purchase for unlimited PDF input (free upgrade for PDiff Express 1.x users)
• in-app purchase for comparison reports as annotated PDFs

• fast and reliable PDF text comparison for multipage documents
• highlighting of differences (changes, insertions, and deletions) in the PDF files
• text synopsis display with synchronized text and highlighted differences
• synchronized side-by-side display of two PDFs: see corresponding words in all displays by hovering with the mouse over the text
• comparison handles layout changes (e.g. single vs. multi column), font, size and style changes, added hyphenation and different page breaks
• spot light display to distinguish text from non-text areas
• thumbnail widget of all differences for quick overview and navigation
• navigable list of differences including differences per character (tool window)
• GUI supports splitting separate windows to work in dual monitor environments
• full text search function
• easy-to-use interface for best user experience
• full Unicode support for international scripts
• retina display support


English, German

• Both PDFs must contain searchable text (i.e. text from scans/images cannot be extracted, neither text from fonts converted to paths)
• PDFs must not be encrypted
• Text is extracted in PDF text order (i.e. regions with multicolumn layouts and tables, should have the same text order - row first or column first - in both documents)
• To test above requirements, open your PDFs in check if text is searchable and inspect text order by selecting growing regions with the mouse.

What’s New

Version 2.3.3

• Fix: Compatibility with new Apple M1 chip

Ratings and Reviews

1.0 out of 5
3 Ratings

3 Ratings

hbertacc ,

Crashes - Not working

I tried to use this application with simple PDF files. It crashes right away when trying to open the first file to compare.

Developer Response ,

Thank you for your review. Please contact our support by e-mail in order to find a solution. Thanks again!

Tzofee ,

Poor execution

Doesn't work well. It is easier probably to compare without it :(

Developer Response ,

Could be a problem with your PDF files. For many other users, the software has proven very useful. They do not want to miss it anymore because comparison with PDiff is so much easier than without it. 

Please feel free to contact our support so that we can help you achieve an optimal user experience, too. Thanks!

~Buck+12 ,

Dont waste your money

Very expensive for what you get. Inaccurate comparisions, horrible interface, no help.

Developer Response ,

We fully agree with you, no one should waste their money! That is why we offer PDiff Express under a freemium license. Before you spend a single cent, you can thoroughly check the free version with your PDF files.

There is a zillion of PDF files in the wild created by hundreds of different creator programs. Your mileage with PDiff may vary because comparison results will depend more on the internal structure of the PDF files than simply viewing or printing them. However, with regards to accuracy the software will, in principle, never show too few differences but rather more differences than possibly expected.

Over the past few years, we have learned that PDiff does a pretty good job for most users and most input files. If you have persistent problems with the app, please feel free to contact our support. We will do our best to help you to get the best out of the app. Thank you!

App Privacy

The developer, CSci Computer Science, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer's privacy policy.

Data Not Collected

The developer does not collect any data from this app.

Privacy practices may vary, for example, based on the features you use or your age. Learn More


CSci Computer Science
23.3 MB

macOS 10.13.0 or later, 64-bit processor

Age Rating
In-App Purchases
  1. Unlimited PDF input $35.99
  2. Annotated PDF Reports $17.99
  3. Upgrade from PDiff Express 1.x


  • Family Sharing

    With Family Sharing set up, up to six family members can use this app.