All the browsers on my machine report my resolution as 1080p despite using 4k. I assume this is because I run at 200% scaling (I believe this is relatively common among anyone using a 4k resolution)

If the above-linked website uses data reported by the browser, I wonder how this scenario might be taken into consideration (or even if such a thing is possible)

Remember the days when you would be in danger of your apartment being burglarized and thieves would take your TV or receiver or CD player etc.? Nowadays that's called junk removal and you pay for it! How times have changed...

> Does 4k matter?

The PC I'm typing this on has two 27in 4k screens. I'm sitting so that I look at them from about 75cm away (that's 2.5 feet in weird units).

I archive most of my video files in 720p, because I genuinely don't see that big of a difference between even 720p and 1080p. It is definitely visible, but usually, it does not add much to the experience, considering that most videos today are produced to be watchable on smartphones and tablets just as much as cinema screens or huge TVs. I only make an exception here for "cinematic" content that was intended for the very big screen. That does not necessarily mean movies, but also certain YouTube videos, like "Timelapse of the Future": https://youtube.com/watch?v=uD4izuDMUQA - This one hits differently for me in 4K vs. just 1080p. Having to watch this in just 720p would be tragic, because its cinematography relies on 4K's ability to resolve very fine lines.

So why would I make a point to have both my screens be 4K? Because where else do you look at fine lines a lot? You're looking at it right now: Text. For any occupation that requires reading a lot of text (like programming!), 4K absolutely makes a difference. Even if I don't decrease the font size to get more text on screen at once, just having the outlines of the glyphs be sharper reduces eye strain in my experience.

Curious to hear more about the a11y work.