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New user of Sumatra since a friend recommended Ninite, I have only used Sumatra on all computers I own!

Issue 1, multiple windows, I know a fix is coming soon! so that’s okay

Issue 2. I have a Dell XPS 13 (2in1), docked below 2 of my 1080p wall-mounted displays,
so the laptop sits centrally below two HD screens.

now the laptop is ‘4k’, when I open Sumatra, which usually opens on one of the 2 external displays, upon dragging to my XPS it becomes blurry, the whole application the document and all the system fonts in the application are blurry, its as if it can not scale, all other applications chrome etc scale just fine when moving from 4k to HD displays

Thanks again

Loving the light weight open source life!


Scaling is very much down to windows control and SumatraPDF generally uses system supplied fonts but Icons are related to screen pixel size so if widows screen is set to 125% the bitmaps will be increased by 25% (not a good setting as pixels by their definition are integers so Windows and its graphics drivers will use interpretation with the result edges become “fuzzy” here are some of my screen shots where windows has changed the scale settings for each screen (normally I keep both at 100% and the righthand one is “fuzzier” than the left)

Here my RH screen has been adjusted to 150% with identical frames of SumatraPDF on each side of the divide. It is fuzzy but as I explained I expect that (its not the main screen).
SumatraPDF upscaled to match the 1.5 x scaling. (Note the text in the background spanning both screens is there just for reference so here it is 100%)

Reversing some settings my left hand main screen is now upscaling by 25% and Sumatra is upscaled but since its my main screen it still looks good whilst the right hand screen is still “fuzzier”


Yes, Sumatra doesn’t currently re-scale when moving window between screens of different resolution.

It’s non-trivial to implement and I don’t have a multi-monitor setup for testing this.


Win10 1803 onwards has a Fix scaling for apps option you can try, or these alternative workarounds.