This paper aims at questioning two diasporic communities settled in Noumea, New Caledonia's capital city. The first consists of those with internal (domestic) mobility (from Lifou and Ouvea, Loyalty Islands), while the second are those from Vanuatu, the product of external (inter-regional) migration. From these case studies, we examine how unevenly they are managed bytthe weight of linguistic norms on everyday language practices of diasporic urban speakers of Drehu, Iaai and Bislama languages. This contribution also investigates the strategies used by diasporic speakers as well as language institutions, like the Kanak Languages Academy, to maintain their languages and preserve their heritage.