About Compare PDF
Inspect two versions of a PDF side by side, with a third view highlighting visible pixel changes. This can help catch layout or wording differences between revisions. It is useful for reviewing contract amendments, updated reports and re-exported documents.
How to use Compare PDF
- Choose the original PDF and the changed PDF.
- Compare corresponding pages side by side.
- Look at the highlighted image for visual differences, then verify them in the source PDFs.
What to check
The comparison renders pages as images and checks corresponding positions. Changes in fonts, spacing or rendering can produce highlights even when the intended content is similar. Treat every highlighted region as a prompt to verify, not proof of a content change.
Limitations
This is a visual comparison, not a semantic text diff. Only corresponding pages up to the shorter document's page count are compared.
Frequently asked questions
Why are unchanged pages highlighted?
Differences in fonts, rendering or compression can change pixels without changing content. Verify highlighted areas in the source documents.
Does it compare text or images?
It compares rendered page images pixel by pixel, so it catches any visible change but cannot explain what changed in the text.
What if the two files have different page counts?
Pages are compared up to the shorter document's length; extra pages in the longer file are not shown.