First of all, I'm going to attempt to make my own pet profile with little to no actual knowledge of coding, WISH ME LUCK! lmao.

Anyway... if I make a pet profile with a full-size, non-repeatable background, what would be the best size to suit most people's screens?

Do you think it would be better to do it slightly smaller and then put a repeating background behind the main bg image so it doesn't look completely awful on bigger screens, rather than make it the biggest size and have people on smaller screens have to scroll to see all of the bg?

in this day and age, there really isn't such a thing as "best size" anymore; things should be responsive to accommodate for multiple viewing platforms, including mobile.

if you just want the image to take up the whole page, you can use "background-size: cover" to make it scale with the window. in that case you'd want the image to be very large, probably around 2000px wide or more.

if the background image needs to be a specific size to properly align with the page content, then i'd say keep it around 1000 x 700 and utilize some sort of pattern behind it to create a more seamless transition.

That's a good point! Last time I was on Subeta, smart-phone use hadn't really taken off yet (you can see how long it's been since I've been here or made a profile lol). Thanks for the tips :)

lmao yep when i was first taking web design a few years ago they were still teaching us to size things with 1000x700 in mind. the following year, the professor said to forget all that and make everything responsive bc most people are browsing on their phones and tablets anyway :P