On the main photo of your profile VKontakte you can put a file with a minimum resolution of 200 by 200 pixels and with a maximum width of 500 by height. Particular attention should be paid to the choice of a square thumbnail that usually appears near your comments and entries.
All original photos uploaded to the social network are processed by a special algorithm with some degree of blurring. To improve the quality of the uploaded images, it is worth posting horizontal photos with a maximum resolution of 1000 pixels by width and vertical – in 700. In order to avoid the appearance of a strong blur, VKontakte experts recommend to increase the sharpness of photos independently.
An image uploaded to a Facebook user’s avatar is usually trimmed into a square. Therefore, it is better that the original photo already has square proportions of at least 180 pixels.
Facebook social media user cover.
The minimum size of a photo uploaded to the cover of a Facebook page should be at least 400 by 150 pixels. However, a picture of such a tiny size will be neglected to stretch to standard sizes of 815 to 315 pixels, so it is most logical to use photos of the corresponding parameters.
Photos to the social media album Facebook.
The recommended options for uploading a photo to an album are 600 by 400 pixels.