Pixel Dimensions for Profile and Cover Images

[+Hoiditthroughthegrapevine he/him]

Is there an optimal specification for pixel dimensions for Profile pictures and Cover images?

I was turning some art into profile and cover images recently and I noticed there's quite a bit of variation in how they can display on desktop and mobile, especially the cover image. Some images were cropped sometimes, sometimes they weren't proportionally scaled, but they all seemed to be based on image positioning from the top left hand corner.

The site is great, and it looks great, it would just be nice to know the technical details of what is going on under the hood especially with cover image scaling/positioning.

I think this is the right place for this question, and thanks again for all that you guys do to make this the nicest forum on the internet!

[Chaos he/him]

For profile pictures, 200x200. Square is good. I'm not entirely sure about cover images right now.