How to compare two PDFs

Compare two versions, step by step

1. 1

   Choose the two files

   With nothing open, choose File › Compare… (⌥⌘C) and pick both PDFs, or click Compare on the start screen. With a file open, Compare with… asks for the other one; the open file goes on the left.

2. 2

   Let them be read

   Each file is read as it is on disk, on your computer; scanned pages take a few seconds more. A password-protected file asks for its password.

3. 3

   Step through the changes

   The list down the side names every change; choose one and both columns scroll to it. Next Change (⌘G) and Previous Change (⇧⌘G) step through them, and the two columns scroll together page by page.

4. 4

   Save a report if you need one

   Save comparison report… writes a new PDF of the differences to keep or send. Neither compared file is changed.

Comparing and viewing the differences is free; saving the report needs a licence.

What it finds

• Words removed, marked in coral on the older file.
• Words added, marked in mint on the newer file.
• Words changed, marked in yellow on both.
• Pictures that differ, outlined in yellow.

Colour is never the only sign: every change is also in the list, by page.

Other ways to compare PDFs

• Adobe Acrobat Pro has a Compare Files tool; Adobe's pricing page lists it in Pro and Studio, not Standard. See Latte PDF vs Adobe Acrobat.
• PDF Expert lets you look at two files side by side in split view. See Latte PDF vs PDF Expert.
• By eye. Two windows side by side work for a page or two, but changes in a long contract are easy to miss.