Is watching 4K video on an iMac possible?

[MacknTosh]

And by that I mean, when I go toYouTube and look for a 4K video (i.e. 2160p), in Safari I only get the option to watch at 1440p. Having had a google (as one does) I see lots of stories about YouTube pushing something called VP9, whereas Apple are embracing HEVC (it's all letters to me). However even when I go to Firefox, I can still only watch at 1440p max. I'm using High Sierra on a 27" iMac so have the screen to watch 4K video, but I'm never given the option. I'd just like to see what it looks like as my next TV will be 4K (assuming it looks worth it picture wise).

 

[mzanker]

Yes, it's possible, but you'll need to use Chrome.