We have screen resolution but very often user has mutiple browser toolbars resulting in quite small actual window size. This information is very useful for designing websites as you need to know smallest size you need to cater for. Full screen resolution doesn’t tell you that. So an enhancment to existing UserSettings plugin to report window sizes would be very useful.
This feature is logged in Piwik’s Trac system : Option to report Browser Window size instead of resolutions · Issue #983 · matomo-org/matomo · GitHub
I was among the people asking for this one or two year ago…
But, browser window size is not the same thing as viewport size.
At least not vertically.
Also, it may be interesting to observe how these values develop. I can imagine that there’s a lot of different values for window width and height, so the usual grouping of exact values would be useless. There should probably be some clustering like for the visit duration time, or rounding all widths and heights to the closest multiple of 10, and generate separate statistics for width and height.
Hm, analysing window width and height independently is probably pretty useless because you won’t know whether half of the windows were wide, or high, or both, or none.
What about this visualisation: First round each values to multiples of 10 (or whatever value works for you). Then draw a rectangle outline for every window size that occurs. The higher the occurences count, the darker the line. A light rectangle indicates a low number of visitors with that window size, a dark colour stands for more visitors with that window size. All outlines are drawn on top of each other, either centered to the middle or aligned to the top left corner. Then, some smart code could formulate statements like “50% have 1100 by 730 px space or more and 90% have 900 by 600 px or more”.