How do you track changes on a PDF?
Written by Cameron James·July 2, 2026Quick answer
PDFs don't have a built-in track changes feature like Microsoft Word, so you track changes on a PDF either by comparing two saved versions or by marking the file up with comments. The cleanest method is Adobe Acrobat Pro's Compare Files tool, which analyses an old and a new version side by side and highlights every text, image and formatting difference. If you only have the free Adobe Reader you can't run a comparison, but you can use the comment and markup tools to record proposed edits during a review.
Key facts
- PDF has no native, live track-changes mode. Unlike Word, it doesn't record edits as you type, so you track changes after the fact by comparing versions or annotating.
- Adobe Acrobat's Compare Files tool needs two separate saved versions (an "old" file and a "new" file) and produces a report highlighting the differences.
- Compare Files sits only in the paid tiers (Acrobat Pro, Premium and Studio), not the free Adobe Reader.
- You can review results in a side-by-side view or single-page view, and filter by change type: text, images, formatting, headers and footers, annotations and backgrounds.
- For collaborative edits, the comment and markup tools (sticky notes, highlights, text insert and delete) let reviewers flag proposed changes manually, and these work in the free Reader.
- A common workaround is converting the PDF to Word, using Word's Track Changes, then exporting back to PDF, though the round-trip can disturb the layout.
- Third-party editors like PDFelement and PDF-XChange Editor offer their own compare and annotation features as Acrobat alternatives.
Two jobs hiding under one question
The thing to understand is that PDF was built to look identical everywhere, not to keep its own edit history, so there's no live track-changes toggle the way there is in Word. Every method here is really one of two jobs: comparing two versions you've already saved, or annotating a single file so people can propose changes.
Compare Files does the first job well, but it only works if you actually kept the earlier version, so save your drafts as separate files or you'll have nothing to diff against. The comment tools do the second job, and they're your only real option in the free Reader. The Word round-trip is fine for a heavy text edit, though it can scramble tables and spacing, so always check the layout before you send anything that matters.
A diff report isn't the finish line
Here's the bit those tutorials skip. A Compare report tells you what changed, but it does nothing for the person on the receiving end. When I was sending revised contracts and decks all day in growth roles, the other side almost never ran a diff to spot my edits, they just skimmed the new version and missed half of what had moved.
If the point of tracking changes is that someone understands them, a highlighted comparison report sitting in your own inbox isn't the finish line. That's the gap we built LiveDocument around: pairing the PDF with a short video walkthrough behind one link, with clickable highlights that jump to the exact sections you changed.
The Bottom Line
To track changes on a PDF, use Acrobat Pro's Compare Files for a clean version diff and the comment tools for a review cycle, but remember a comparison report only ever tells you what changed. Getting the other side to actually take in those changes is a separate problem, and it's the one worth solving when the document matters.
Written by Cameron James