Historically, 255 characters has often been the maximum length of a VARCHAR in some DBMSes, and it sometimes still winds up being the effective maximum if you want to use UTF-8 and have the column indexed (because of index length limitations).Historically, 255 characters has often been the maximum length of a VARCHAR in some DBMSes, and it sometimes still winds up being the effective maximum if you want to use UTF-8 and have the column indexed (because of index length limitations).