The field of linguistic landscape has rarely engaged with the growing number of metrolingual practices brought about by online digital spaces. This paper examines the online linguistic landscape of social media platforms, which presents a spatial repertoire of innovative semiotic affordances. Adopting an online ethnographic approach consisting of screenshots of WeChat Moment posts and semi-structured interviews and drawing on the researcher's ethnographic knowledge of the participants, the study examines how participants in this online space draw upon a complex array of semiotic resources from spatial repertoires to constantly negotiate their self-presentation and manage the effects of context collapse. The analysis shows that metrolingual practices have contributed to self-policing of content, manipulation of accessibility, and compensation for literacy in the online linguistic landscape. By tuning the analytical focus from offline to online spaces, the study expands the scope of linguistic landscape research and invites further examination of the relationship between language and space.