Free online PDF tool
Compare two PDFs visually with pixel-perfect diff
Compare two versions of a PDF to spot changes in text, images, layout or formatting. PdfWiseAI renders both PDFs side by side and produces a difference report showing exactly which pages differ and by how much.
Use Compare PDFsHow it helps
A straightforward way to work with your document
The comparison runs entirely in your browser. Each page of both PDFs is rendered at the chosen quality, then a pixel-by-pixel diff is computed. The downloadable PDF highlights differences in red, while the on-screen summary lists affected pages and percentage difference.
Both PDFs stay on your device. No server upload, no sign-up and no data is retained by PdfWiseAI.
Three simple steps
How to use Compare PDFs
- 1
Select the first PDF (original version).
- 2
Select the second PDF (revised version).
- 3
Choose the rendering quality for comparison.
- 4
Review the visual diff report and download the summary.
Professional use cases
When a private browser-based workflow helps
This workflow is useful for legal teams assembling exhibits, finance staff preparing statements or tax records, healthcare offices organizing administrative documents, and anyone handling files that should not be copied to an unnecessary conversion server.
PdfWiseAI creates a separate result and leaves the source unchanged. Review page order, image quality, visible content and the output filename before sharing the generated file.
Privacy verification checklist
Check the workflow before using sensitive documents
- Use a harmless sample file first and confirm the expected output.
- Prefer local transformations when no AI analysis is needed.
- Follow your organization’s security, legal and records policies.
- Keep originals until the generated file has been reviewed.
Local processing reduces document transfer, but it is not a certification of compliance with HIPAA, attorney-client duties or another regulatory framework.
Frequently asked questions
Compare PDFs FAQ
Are the PDFs uploaded?
No. The comparison runs entirely in your browser.
What output is produced?
A downloadable image-based PDF and an on-screen text summary listing changed pages.
Can I compare scanned PDFs?
Yes. The tool renders pages visually so scanned documents work the same as digital PDFs.
Does it work for text changes?
Yes. Any pixel difference — text, images, layout — is detected.
How is the difference calculated?
Each pair of pages is rendered at the chosen quality and compared pixel by pixel. Changed pages are highlighted in red on the downloadable diff PDF.
Can I compare password-protected PDFs?
Both PDFs need to be unlocked before comparison. Use the unlock step first, then return to the compare tool.