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This file [link removed, see new link below] works fine in Adobe Acrobat, but when I open it in Sumatra 3.1.2 (tested in two different computers) it is very slow at rendering, and page 11 is blank. I’ve experienced the slow rendering in some other files too. Either Sumatra has a bug, or Acrobat does something special…


[Later Edit] There appears to be a potential flaw in that file since on running various attempts to optimise the file it frequently (depending on repair options) shows a blank page 11

The simplest repair in this case is to use Angus Johnsons PDFTK Gui
thus if you split the 16 pages and rejoin them again they do not change quality (still a tiny bit slow to render due to the image compression) but it removes the linearization and corrects any hiccup around loading page 11

That document is Linearized (suitable for web viewing slowly page by page) it would need to be “de-linearized” to work quickly, part of the issue is that its more than 10mb so SumatraPDF does not load it all into memory thus will have a slowdown around page 10 or once you get to page 16 then page 5 will be slow etc. The reason for the large size is the fairly high dpi (300) when many pdf’s use 120-150-200 dpi If I recompress to 200 dpi it is not degraded noticeably in quality and due to recoding it is still about 14 Mb however it loads significantly faster and is very quick to scroll around without the rendering message

Page 11 renders fairly quickly for me but I’m using SumatraPDF-prerelease-11040 see can you see if that makes a difference for you ?


Yes, with SumatraPDF-prerelease-11040 page 11 works and overall rendering speed seems a little better.

In the program I used to create the pdf there was a “Save As optimizes for fast Web view” setting I didn’t know of. I tried to remove that setting and recreate the pdf ex novo, but nothing changed in Sumatra.
If I reduce optimization of page 11 a little, it works on Sumatra too.
If anyone wants to do tests with Sumatra, I’m leaving non-working page 11 alone here.


Will add that page to my collection of oddities to test over time, however at present I can’t see it in my current firefox or ie (in both its a blank sheet) only if I download can I see the content with latest SumatraPDF so that pdf page does seem to have some issue.


I think I understood where’s the problem. Adobe Acrobat was set to compress images with JPEG2000 standard, which is better than basic JPEG. If set to basic JPG, Sumatra opens the files quickly. So, if Sumatra has a fault, it’s low efficiency in reading JPEG2000


Is it possible to change 10MB limit to more? Like 500MB or 1GB? I guess that would solve fast loading problem if more data was loaded in memory. I have enough RAM, most people do, its not 256MB RAM PCs era anymore.


Note 10 Mb has been raised to 32 Mb in latest pre-release