Ability to Overlay Comparison of PDFs and Drawings

DawidB · Post by **DawidB** » Wed Aug 20, 2025 12:22 pm

Hey,
I’ve got a feature idea that could make comparing engineering drawings a lot easier. It’d be great if users could stack two PDF drawings on top of each other. For example, Drawing 1 could show up in red and Drawing 2 in green (with the option to change colors). Wherever the lines overlap, they’d turn black.
Another thing that would be super helpful is the ability to move and rotate freely Drawing 2 relative to Drawing 1, since parts of a design often shift around on the 2D canvas. Being able to align them properly would make comparisons way more accurate.

Willy Van Nuffel · Post by **Willy Van Nuffel** » Wed Aug 20, 2025 1:56 pm

Hello,

You can try the solution explained here:
viewtopic.php?p=193211#p193211

Kind regards.

Wed Aug 20, 2025 10:09 pm

codyag777 · Post by **codyag777** » Wed Sep 17, 2025 5:04 pm

Hi - did this get updated? If so is it in PDF Xchange?

Post by **Paul - PDF-XChange** » Wed Sep 17, 2025 5:05 pm

Hi, codyag777

is this what yo are looking for?

image.png

codyag777 · Post by **codyag777** » Wed Sep 17, 2025 5:21 pm

Yes but I am missing the color options:

image.png

codyag777 · Post by **codyag777** » Wed Sep 17, 2025 5:42 pm

NVM, I see I needed to download latest update, it is showing now.

Wed Sep 17, 2025 5:50 pm

codyag777 · Post by **codyag777** » Wed Sep 17, 2025 7:22 pm

Is there a blog or some kind of post you guys can do to show how to compare PDFs printed from CAD drawings to show changes? I.e. recommended settings, procedure, etc?

Wed Sep 17, 2025 7:27 pm

Hello, codyag777

I believe closes thing at the moment would be my post which Willy linked to above:
viewtopic.php?p=193212#p193212

In practice, the full extent of the recommendations is "use red and blue, with the blend mode set to 'multiply'". That will ensure anything that perfectly overlaps appears "black" and the rest will be clearly colored as red or blue for document A or B.

I will see about having a KB article made up detailing the process in the future.

Kind regards,