This paper conceptualises the ways grassroots innovations (GIs) influence sustainability transitions. While research on GI diffusion tends to use the three-pathway model (replication, scaling up and translation), this paper rethinks GI diffusion through the lenses of an embedding framework. We illustrate this framework by applying it to the empirical case of ecovillages in the Global North and South. The results show that GIs become embedded in wider society through different dynamics: expansion, reframing, circulation of knowledge, shifting material arrangements and replication. The embedding framework brings clarity to diverse dynamics of diffusion and is particularly able to grasp the cultural, cognitive, economic and environmental impacts of GI initiatives.