One thing that often bothers social media workers is the size of the cover image on the Facebook page. What size should it be and why doesn’t everything show up on mobile? According to Facebook, the cover image of the page appears 820 pixels wide and 312 pixels high on computers and 640 pixels wide and 360 pixels high on smartphones. To make the job and layout designing easier, I made a template for Photoshop (.psd) and will now share it here as well. If that image changes in size (and when it changes), I will update the new template on this page!
There are two layers in the file, from which you can see what is visible from the cover image on Desktop and Mobile. The so-called safety area where you should place it most important. I hope this helps you too!