Recent years have witnessed the rise of digital platforms that allow economic agents to arrange ever more ﬁne-grained contracts. This article zooms in on labour-based platforms that permit the hire of labour in a just-in-time fashion (and are part of the broader trend towards on-demand work). Its principal contribution comes in three parts. First, exposing the frequently overlooked diversity of labour-based platforms, the article proposes to distinguish platform companies, which directly sell services and then purchase the labour needed to provide them, and broker platforms, which act merely as intermediaries. Second, it examines how platforms of each type pose distinct threats to labour justice, thereby extending Daniel Halliday’s (2021) analysis. Drawing on empirical studies of the experiences of platform workers, it identiﬁes a power imbalance as the root cause of these threats across all platforms. Finally, the article assesses three strategies to counter these threats: introducing stricter regulation, turning platforms into worker-run co-ops, and improving outside job opportunities. In exploring how each strategy could be implemented for speciﬁc platforms, it makes the case for always discussing labour-based platforms with one eye to their speciﬁc structural features and the other eye to the broader labour market.