Feature request: Compare pdf visually

[sbp]

Dear Tracker team,

since 9.3 you came up with some rudimentary pdf compare options.

We use pdfxchange on drawings a lot and therefore would be interested in a visual comparison between two files.

There are a few options out there, but we would prefer to have this included in our favourite pdf viewer:

We want something like this:

image.png

and

image(1).png

Basically an overlay of two pdfs would be great. One with color green, one with red and then everything is black where they are exactly the same and green/red if something is new or has been erased.
I experimented with your pdf overlay options, but as you cannot colour the pdfs and you have to give a certain opacity this is of limited use.

Have a look at these two options, that can do it.
https://www.parepdf.com/
https://github.com/vslavik/diff-pdf


Furthermore it would be great to not only see the documents side by side, but also overlayed as shown above.

Do you think that something like this could be added? And if so, can you give a very very rough estimate, how long this would take to be added? Weeks / months / a year / multiple years??

Depending on this, we would seek for other options in the meantime, until our beloved pdfxchange has the capabilities.

[Daniel - PDF-XChange]

Hello, sbp

This is an item we have seen a fair few requests for over the years, it has not been rejected, but it is not a priority at this time.
RT#4309: FR: Temporary overlay for comparisons

I am afraid that cannot offer an estimate on timeline in any capacity. It is possible the Devs will tell me next week that its done, but it is just as likely that I wont hear anything on it for the next year.

Kind regards,

[Yorgi]

Just a note that this can be accomplished with the OVERLAY PAGES tool. Overlay one page into a blank document and set the color to red and 60% opacity, then overlay 2nd document and set color to green and 60%. Use Multiply Blend Mode for both.

[Daniel - PDF-XChange]

Hello, Yorgi

Thank you, yes, the Compare tool was finally added in response to this request, sorry for neglecting to post the solution here at the time.
For anyone reviewing this later on, the options Yorgi mentions are here:

image.png

Kind regards,