Compare PDFs Online: A Practical Step-by-Step Guide
Compare two PDF documents to identify text differences and review revisions before approving or sharing a file.
PDFLeo provides a browser-based workflow for this common document task. The safest approach is to work from a copy, check the result carefully, and keep the original until you know the output is correct.
How to use Compare PDFs
- Keep both versions and identify which one is the earlier draft and which is the new version.
- Open Compare PDFs and select both documents.
- Run the comparison and review the differences shown by the tool.
- Check important changes in the original PDFs, especially figures, tables, signatures and page layout.
Best practices for reliable results
- Keep an untouched backup of the source document.
- Use a file you have permission to process and share.
- Review every page of the output, not just the first page.
- Check text, page order, links, forms and images where relevant.
- For important work, compare the output with the original before sending it to anyone.
Limitations to know
Text-based comparisons may miss visual-only changes, scanned text, layout shifts or changes in embedded images. A comparison is a review aid, not proof that two documents are legally equivalent.
Frequently asked questions
Can it compare scanned documents?
Results depend on whether readable text is available. Should I review the original pages? Yes, particularly for contracts, numbers and signatures.
Should I delete the original after conversion?
No. Keep the original until you have checked the result and confirmed it contains everything you need.
Related PDF help
Explore the complete PDF tool guide library or browse the PDFLeo blog for more practical document tips.
Last reviewed: October 2026. Tool behavior can depend on file structure, browser support and the selected options. Always verify your output.