Compare PDFs
Compare two PDFs side by side and highlight visual changes in red.
Your files are ready.
Preview or download the results below. Your originals have not been changed.
How to use Compare PDFs
- Choose your documents. Use the file picker or drag them into the workspace. Files are read locally on your device.
- Check your selection. Visual comparison is not semantic text comparison. Inserted pages, font rendering and compression can affect results. Up to 40 MB per PDF and 100 pages.
- Process and download. Save the finished files, then check the result before using it. Your original files stay unchanged.
What this tool does
Inspect original, revised and difference previews page by page. Adjust pixel tolerance, check all pages, and download a difference PNG or page-summary CSV. Corresponding pages align at the top left at equal scale.
Before you start
Visual comparison is not semantic text comparison. Inserted pages, font rendering and compression can affect results. Up to 40 MB per PDF and 100 pages.
Each PDF can be up to 40 MB. Very large documents or high-resolution images may need more memory than a phone can provide. Choose a smaller file if your browser runs out of memory.
Your files stay with you.
File contents are processed on this device. We do not upload your selected files to a server or save them to a Pactuno account. Closing or clearing the page releases this session’s files. Downloaded results remain wherever you save them.
Read the tools privacy detailsQuestions, answered.
Is Compare PDFs free?
Yes. This tool is free to use without an account. You can process files again as needed, within the per-run limits shown above.
Can I use it on my phone?
Yes, in a current browser with JavaScript enabled. Larger files may work better on a computer with more available memory. Processing depends on your device, not a server queue.
Will this preserve a signed or protected PDF?
Editing a PDF changes the document and invalidates existing digital signatures. Password-protected PDFs are not supported. Use an unlocked copy you are authorized to modify, and review the output.