Abstract Interest in the use of digital resources by migrants is growing in sociolinguistics research, given the central role that digital technologies and social media platforms have in their migration process, in the establishment of communities of belonging, and in the creation and negotiation of identities. However, most sociolinguistic research has focused on digital diasporas and their use of different technologies and spaces. In our paper, we investigate a little-explored context: the communicative strategies used on Facebook by multilingual migrant youth who do not belong to a diasporic community, but rather form their own attachments to others based on their migration trajectories. Taking up Lexander and Androutsopoulos’ (2023) concept of ‘digital polycentricity’, our focus is on how these young people navigate their orientation to different centers loosely defined as ‘home’ and ‘local’ communities and on how their developing use of linguistic and semiotic resources responds to the changes in their experiences and language repertoires. We show that online communication with members of the local community is centered on specific topics, styles and the use of what we have called a ‘digital translingua’, a unique form of multilingual and multilectal writing formed through a mixture of different linguistic and semiotic resources which constitutes one aspect of their multimodal digital translingual repertoires. Our paper contributes to the study of polycentric digital communication but also to the investigation of multilingual non-diasporic communities within specific virtual spaces.