Square faces have an square hairline and an angled shortish jaw. Because their face is overall shorter (closer to their width being similar to their length), they will want to elongate their face with their hairstyles.
Hairstyles that work for a square face
Add either height or length, but not width.
Side swept fringe (bangs)
Side part with straight hair that goes past the jaw (such as a longish concave bob)
If you have short hair, keep the back and sides trimmed and add volume at the crown, the quiff can work for you.
Graduated long layers can work really well. The first of your layers should start at your chin.
If you have wavy hair, keeping your hair either really short or longer will work best. That way the length of your hair will help to weigh it down so that it doesn’t add too much width.
If you pull you hair back into a ponytail, add some volume at the crown to give you some lengthening.
If you have curly hair, keep it either short, with volume at the crown, but not the sides, or wear it long past your shoulders.
Length, layers and waves are your go-to elements of a hairstyle!
Hairstyles that should be avoided for a square face
Heavy blunt fringe, it will further shorten and widen your face
A bob that ends at the jaw will highlight your square jaw
Short, wavy or curly hair with volume at the sides of your face
Unless your face is very symmetrical, avoid a centre part