Compare PDF
See what changed. Review revisions with a red and blue overlay.
How to compare pdf
- 01
Choose the original as Revision A and the update as Revision B.
- 02
Review red removals, blue additions and black matching content.
- 03
Inspect each page and save an image or review report.
Before you share the result
Pixel differences identify visual changes, not engineering correctness. Use matching page sizes and origins.
Keep the original document until you have checked the output. Password-protected or damaged PDFs may be rejected. Large drawings can require a lower render resolution.
Frequently asked questions
What does it compare?
The comparison is visual and pixel-based, so it detects linework, text, images and other rendered page changes.
Are documents uploaded?
No. Both PDFs are rendered and compared locally in your browser.
What if page sizes differ?
For reliable alignment, compare PDFs exported at the same page size, orientation and origin. The tool pads smaller pages with white space.