The background image is at the top of our profile in the form of a “header” photo, and its shape is rectangular.
Facebook accepts the image size of cover photo: 820 x 312 pixels, but the better solution is to use 960 x 365 pixels. If you have graphics with very high resolution, then the recommended size of the graphics is 1656 x 630 pixels.
Important additional information: photo in the background, does not fully adapt to mobile devices, so some items that are located may not be visible (automatic cropping on the mobil).
We recommend the size of cover image for the group: 1640 x 924 pixels.
Free facebook cover 2019.
Here you can download free PSD templates of header (package include font too):