Online spaces are increasingly important in the sale of food, alcohol and tobacco. This analysis focuses on two developments in online food delivery: delivery-only 'dark kitchens' and rapid grocery delivery services (RGDS), with the aim to understand and assess the availability of health harming and health promoting products through these services. Data was collected for one metropolitan local authority in London, UK, using publicly available online sources. Being explorative in nature, the analysis includes descriptive statistics and qualitative assessment. Three dark kitchens (renting kitchens to 116 food businesses), three grocery delivery apps, and 76 grocery businesses available through online delivery platforms were identified. Most businesses renting dark kitchen space were 'virtual restaurants' (52%) selling fast food (47%) or dessert (21%) through online delivery platforms. RGDS sold a variety of items, with a focus on pre-packaged foods high in fat, salt and sugar, alcoholic beverages and tobacco. These items were also most likely to be promoted through offers and promotional language. Fruits and vegetables were less commonly available and mainly on grocery delivery apps. Online delivery services increase the temporal and geographic availability and promotion of many unhealthy products. Research expanding on the geographic area of interest is needed.