The Gilaki language is closely related to Mazanderani, and the two languages have similar vocabularies. The language is divided into three dialects: Western Gilaki, Eastern Gilaki, and
Galeshi (in the mountains of Gilan). The western and eastern dialects are separated by the Sefid River. According to Ethnologue, there were more than 3 million native speakers of Gilaki in 1993. By 2006 there were 4 million native speakers of Gilaki.
There are three main dialects but larger cities in Gilan have slight variations to the way they speak. These "sub-dialects" are Rashti, Rudbari, Some’e Sarai, Lahijani, Langerudi, Rudsari, Bandar Anzali and Fumani.
A slightly different style of Gilaki (Eastern dialect) is spoken in the city of Ramsar, Mazandaran. The dialect has been influenced by the Mazandarani language and is sometimes referred to as Mazandarani-Gilaki or Gil-Mazani although most refer to it as Ramsari.