How to Compare Two PDFs Free

What this is

A visual comparison. Both files are drawn page by page and shown in one scrolling view, so the pages stay aligned. Turn on Highlight pixels that differ to paint changes in red on the right-hand page.

It does not read the wording with a model and it will not write a summary of what changed. If a site calls that "AI compare," this is the honest version: pixels.

How to compare two PDFs

1. Open Compare PDFs.
2. Upload the first PDF, then the second.
3. Leave highlight off for a plain side-by-side, or turn it on.
4. Click Compare PDFs. Scroll the pairs. Download comparison.zip if you want the images.

Limits

Up to 100 pages, because every page is rendered to an image. Split a longer file first.

Privacy

Both files stay in the browser. Comparing them does not send either one anywhere.