When this tool is useful
Spotting layout, image, stamp, or visible text changes between two known versions before human review.
How local processing works
PDF.js renders paired pages at a bounded resolution; pixel differences are calculated locally and shown as a visual result.
How to use it
- Prepare Compare two PDFs visually: Work from a copy and confirm document order, equal page counts, same-index page pairing, render scale, matching page sizes, and the fixed pixel-difference visualization. Keep the source unchanged.
- Apply Compare two PDFs visually: Process locally in the browser. PDF.js renders paired pages at a bounded resolution; pixel differences are calculated locally and shown as a visual result.
- Download and verify: Save under a new name. First confirm equal page counts and matching page sizes, then review every reported difference beside both originals and verify critical text or signatures with appropriate specialist tools.
Important limitations
This is not semantic, legal, accessibility, font-object, signature, metadata, or malware comparison; rendering noise can create differences.
Verify the downloaded result
First confirm equal page counts and matching page sizes, then review every reported difference beside both originals and verify critical text or signatures with appropriate specialist tools.
Private by design
Your files stay in this browser. The tool does not upload the source or output to our servers.
Questions and answers
When should I use Compare two PDFs visually?
Spotting layout, image, stamp, or visible text changes between two known versions before human review.
What does Compare two PDFs visually change?
PDF.js renders paired pages at a bounded resolution; pixel differences are calculated locally and shown as a visual result.
Which limits and settings matter?
document order, equal page counts, same-index page pairing, render scale, matching page sizes, and the fixed pixel-difference visualization. This is not semantic, legal, accessibility, font-object, signature, metadata, or malware comparison; rendering noise can create differences.
How do I verify the result?
First confirm equal page counts and matching page sizes, then review every reported difference beside both originals and verify critical text or signatures with appropriate specialist tools.