Compare PDF
Put two versions side by side to see exactly what changed — words, numbers, stamps or whole pages added.
What to compare
Which words were removed or added — from the PDF text layer.
Also catches non-text changes: stamps, signatures, pictures, layout.
Add both the old and the new version to compare.
Compared on your device — neither file is uploaded.
How to use
- Add the old version (original) and the new version (edited).
- Choose to compare text, page images, or both.
- Press “Compare”: pages are paired automatically, even when the new version inserts or removes pages.
- Review each text change, or view both versions overlaid (red: only in the old version, blue: only in the new one). Download the change report if needed.
Current limits
- Text comparison uses the PDF text layer. Scans/photos without a text layer can only be compared visually — run text recognition (OCR) first to compare their text.
- Visual comparison runs at screen resolution: very small changes (a single dot) may be missed; scans may show small differences caused by scanning or compression.
- Text is compared word by word; differences only in spacing or line breaks are ignored. Text order follows how the file stores it — multi-column layouts can make changes look larger than they are.
- The result helps proofreading; it does not replace checking important clauses yourself.
Frequently asked questions
Will an inserted page throw the comparison off?
No. PDF Tool Plus pairs pages by content, so inserted or removed pages are reported separately and the remaining pages are still compared with each other.
Can I compare two scans?
Yes, visually: pages are aligned (small scanning offsets are compensated) and changed areas are boxed. To compare word by word, run text recognition (OCR) on the scans first.
Are my files uploaded?
No. Both files are read, rendered and compared in your browser on your device.