Read the differences before accepting a revision
This tool compares lines. A changed amount on an otherwise identical line appears as a removal and an addition. The original line number and revised line number help you locate the change without relying on color alone. Longest-common-subsequence matching keeps shared lines in order; moved blocks appear as removal and addition rather than a special move operation.
Windows and Unix line endings are normalized to the same line-break representation before comparison. Case and horizontal spaces remain significant unless you turn on their ignore rules. Ignoring spacing collapses spaces and tabs and trims line edges; it does not remove line breaks or combine paragraphs.
An ignored difference is still worth knowing about. When lines match only because of an ignore rule, the result also displays the original line. The downloaded report records those originals and the selected rules. “Show changed lines only” simplifies the screen; it does not cut unchanged context out of the full downloaded report.
Comparison can show that two extracts differ, but it cannot decide which extract is correct. An OCR error repeated in both versions will not appear as a difference. Check important names, dates and numbers against the actual scanned page. For visual changes to a document’s layout, use the existing PDF comparison tool rather than a plain text comparison.