PDF page compare / diff heatmap

What to know before using it

The same text can create a large pixel diff when fonts or layout change, while a small wording change may look visually subtle. Use Visual and Text modes for different questions, then open changed pages from the summary.

Common failure points

• Scanned PDFs may have no text layer, so text comparison can miss changes.
• Different page sizes turn margins and shifts into visual differences.
• Even a low diff ratio can hide important changes such as dates or amounts.

Practical example

For a revised contract, find wording changes in Text mode first, then use the heatmap to review layout changes.