How to use Compare PDF Files
Choose the original PDF and the changed PDF, pick exact or relaxed matching, then press Compare PDFs. Read the summary and download the report with every difference.
How the comparison works
The text of each PDF is read line by line and the two are matched with a diff, the same method programmers use to compare code. Lines only in the changed file are marked as added, lines only in the original as removed. A sentence with one word changed shows as one line removed and one added, so you can see both versions.
Exact or relaxed matching
Exact matching treats a change of capital letters or spacing as a change, which is right for contracts and figures. Ignore case and extra spaces skips differences that come only from re-typing or re-exporting, so you see the changes in wording.
How it works
Both texts are extracted with PDF.js and compared line by line
Examples
- Worked example
Compare two versions of a contract to see which sentences changed.
Limitations and assumptions
Only selectable text is compared, not images, layout or formatting. Scanned PDFs have no text to compare.
Frequently asked questions
How do I compare two PDFs for differences?
Choose both files and press Compare PDFs. The result counts added and removed lines and the report lists each one.
Does it compare images and layout?
No. It compares the text only, so moved pictures, colours and fonts are not reported.
Are my documents uploaded?
No. Both PDFs are read in your browser and stay on your device.