Reading two versions side by side is how errors survive
Version 3 arrives "with small edits". Reading it next to version 2 feels diligent, but eyes skip: a changed deadline, a quietly dropped clause, one digit in an amount. A structural diff has no such blind spots – every line of both documents is accounted for, and whatever differs is marked. What took an evening of careful reading becomes a two-minute review of the highlighted parts.
The comparison is deliberately text-first: it aligns the documents by content, pairs up edited lines, and marks the changed words inside them. Unchanged stretches collapse, so a forty-page agreement with three edits reads as exactly three highlights plus context.
PDF diff for the documents that matter
Contracts and their annexes are the classic case – for redline-style review of Word originals, use Compare Word Documents, and for a checklist of what to look at when comparing agreement versions, see how to compare contracts. Scanned paperwork becomes comparable after OCR PDF adds a text layer. And when the question is not "what changed" but "is this clause dangerous", hand the file to Contract Analysis.