What matters
Facebook Cover Photo dimensions at a glance
Facebook cover photos display at different crops on desktop (820×312) and mobile (640×360). The profile picture overlaps the lower-left corner, so that area should be kept clear.
The cover is the first large visual on any profile or page. A clean, correctly sized cover builds credibility instantly; a stretched or cropped one looks amateur.
Desktop-optimized covers get cropped taller on mobile, potentially cutting off text. The profile photo overlap can obscure logos placed in the lower-left.