Stayput Tools

How to compare two PDF files and find every change

Someone sends back a contract with "only small changes". You can read both versions side by side and hope to spot them, or let a comparison find them all. It takes a minute, and it is the difference between noticing that a figure or a date was changed and not noticing.

Updated 2 min read

Compare two versions

  1. Add the original PDF first, then the changed one, to Compare PDF. The arrows in the file list swap them.
  2. Wait while both are read. The summary says how many differences there are, and how many were added, removed and changed.
  3. Click a difference in the list to see it marked on both pages, or press Next to go through them in order. Removed words are red on the original, added words are green on the changed PDF.
  4. Switch to "Look of the pages" to compare how the pages look, which also finds changed pictures, logos and layout.
  5. Press Save the report to keep the pages that differ, side by side, and a copy of the changed PDF with the new words highlighted.

What to check beyond the list

  • Numbers: amounts, dates, percentages and clause numbers. A single changed digit is one change in the list, but it can matter more than a paragraph.
  • Moved text: a clause that moved shows as removed in one place and added in another. Check that it still says the same.
  • Pictures and signatures: words cannot compare these. Use "Look of the pages".
  • Page count: if one PDF has more pages, the summary says so.

If the comparison says the PDFs have little in common

When almost every word differs, a list of changes would be a list of everything, so the tool says so instead. Check that you added the right two files, in the right order. If they are scans, make each searchable with OCR PDF first, or compare how the pages look.

Keep a record

The saved report shows only the pages that differ, with the changes marked, and a summary page that lists them. It is a good attachment when you reply to the other side, and a good thing to keep with the signed version. The changed PDF with yellow highlights is handy for reading through a long document that has only a few changes.

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