Facebook profile picture size

Upload at least 320 × 320. Facebook displays it at 176 on desktop, 128 on mobile and 40 pixels in a comment thread — and the 40-pixel version is the one people see most.

Designing for 320 and checking at 40 is the useful discipline here. At forty pixels a face is recognisable and a wordmark is not, which is why almost every business account that uses text in its avatar is illegible in the place it appears most: comment threads and notifications. If the account is a person, use a photo cropped tight to the head. If it is a business, use a symbol rather than a name. Facebook masks the square to a circle, so the corners are lost either way.