It is one of the four Northern Wakashan languages, the others being Haisla (spoken in Kitimaat), Oowekyala (in Rivers Inlet), and Kwakwala (in Alert Bay, Port Hardy, and various settlements).

[3] Heiltsuk is considered to be a dialect of Heiltsuk-Oowekyala, which, like neighbouring Haisla and Kwak'wala, are part of the Northern Wakashan language group.

The resonants in intervocalic forms function similarly to vowels, and so will be charted below.

Heiltsuk has phonemic short, long, and glottalized vowels.

There are mainly three vowel sounds in the Heiltsuk dialect /i, a, u/ which are written as ⟨i, a, u⟩,[5] although nine other sounds are heard as allophones [ɨ, ɪ, ʊ, ɛ, ə, ɔ, æ, ʌ, ɑ].