When two versions of a contract, report or form look almost identical, finding the change by eye is painful. A PDF comparison tool does it instantly. This guide shows how to compare two PDFs and read the results.
Two ways to compare PDFs
Text diff compares the words in each document and highlights exactly what was added, removed or changed — down to the individual word. Visual side-by-side renders both pages next to each other and highlights the regions that differ, which is perfect for layout changes, stamps or scanned documents.
Compare two PDFs step by step
- Open Compare PDF and upload the original and the changed file.
- Read the text diff: green is added, red is removed, and changed lines show the exact words that differ.
- Use the page map to jump to pages that changed, and the next/previous buttons to step through each change.
- Switch to Side by side to see the pages visually, with changed areas boxed.
Comparing scanned PDFs
Scanned PDFs are images — they have no real text layer, so a text diff will look noisy. For a clean comparison, run both files through OCR PDF first (choose the right language, such as Bangla), then compare. Or simply use the side-by-side visual view, which compares the pages as images and works on scans too.
Useful filters
Turn on Ignore case and Ignore spacing to focus on meaningful changes, or Only changes to hide everything that stayed the same. These make reviewing long documents much faster.
Spot every difference: Compare two PDFs now →