People can run into various problems when uploading photos to Facebook from any device, such as a smartphone or computer. For instance, depending on how the file is saved, the photo may publish to Facebook in portrait view when you intended the shot to display in landscape orientation. If this occurs, Facebook allows you to rotate the photo as desired using the website's photo editing options.
Log into Facebook and then click "Profile" on the upper right.
Click "Pictures" on the left side and click the album containing the photo you wish to rotate to landscape. Thumbnails of the album's photos appear.
Click the photo thumbnail that you want to change to landscape. The photo pops up.
Click one of the orientation arrows beneath the "Delete This Photo" option at the lower right corner. The photo turns 90 degrees in the direction you clicked and saves.
Click anywhere outside the photo to finish editing the shot.