PDF revision guide
How to compare two PDF files on Mac
A useful PDF comparison should preserve both sources, explain how pages were matched and keep uncertain evidence visible. The goal is a reviewable change record—not an automatic approval decision.
1. Freeze the two source revisions
Keep the baseline and revision PDFs unchanged. Record each file's name, byte size and SHA-256 hash before interpreting any page difference.
2. Match pages before measuring changes
Use sequence, labels, page geometry and content fingerprints together. An inserted page should remain inserted rather than shifting every later page into a false comparison.
3. Review visual and text evidence
Inspect aligned render differences alongside extracted-text additions and removals. Either signal can reveal a meaningful change that the other misses.
4. Export the settings with the result
Record the pixel threshold, ignored margins, alignment window and unknown states in the receipt so another reviewer can reproduce the result.