How can I compare two PDF revisions and find what changed?

Start with a PDF comparison tool, then use its report as a map for review—not as a final decision about what matters. In Acrobat Pro, open both revisions and choose All tools > Compare files. Select the older and newer PDFs, then compare the full documents or specific page ranges. Acrobat produces a results document with a summary and highlighted differences you can navigate. [S1]

Before comparing, label which file is the earlier revision and which is the later one. Use clear filenames or note the revision dates; a reversed selection can make the report confusing. If you know only some pages changed, you can limit the comparison to those ranges, but check that the ranges correspond to the same material in both files. Save the report alongside the PDFs so another reviewer can follow your notes.

Choose settings that reflect the kind of document and the question you need to answer. Acrobat offers different comparison settings for continuous-flow documents, presentation-style pages, and scanned documents or illustrations. Its scanned-document option compares page images pixel by pixel and can identify reordered pages. [S1]

Text-only comparison can be useful when you are focused on wording, but it ignores graphic differences. If the files contain diagrams, page designs, signatures, charts, or other visual elements, do not rely on text-only results to identify every relevant change. When you are unsure which setting fits, make a comparison and inspect a few representative pages to see whether the report is capturing the kinds of differences you care about. These settings describe Acrobat Pro; other tools may offer different comparison options.

Review the comparison report in side-by-side or single-page view and use its change navigation to move through the differences. Then open the corresponding pages in both PDFs and visually spot-check the relevant content, especially graphics and layout. Acrobat’s report is intended for review; it is not a substitute for inspecting the pages. [S1]

For each flagged item, confirm what changed and note the page in each revision. Also inspect pages where the layout or visuals matter, even if text-only comparison shows no difference. A report can help focus attention, but it should not be treated as proof that every possible difference has been caught or that a change is correct. Treat unclear or high-impact changes as items for a responsible reviewer to resolve.

Keep the log factual and traceable: identify both files, record the page references, describe the observed difference, and mark whether it has been checked. Separate what the report flagged from what you confirmed by looking at the pages. That distinction prevents a highlighted item from being mistaken for a verified or approved change.

For example, using placeholder filenames and hypothetical details:

Earlier file: [manual_rev_A.pdf] Later file: [manual_rev_B.pdf] Page: 4 in earlier / 4 in later Report flag: Text differs in the warning paragraph Visual check: Confirmed; later version changes the final sentence Follow-up: [Reviewer or action needed]

A reusable outline is: file pair and revision labels; comparison settings and page ranges; page references; report finding; visual-check result; follow-up or owner; review date. Leave a field blank or mark it “not checked” rather than guessing. The checklist below can help you apply the same process to the next revision pair.