AbstractObjective:To describe the promotion of food and beverage and marketing strategies used by online food delivery services (OFDS) in a social media platform before and during the pandemic in Brazil.Design:Publicly available data were extracted from OFDS Instagram accounts. Posts published 6 months immediately before and after the first case of COVID-19 in Brazil were randomly sampled. Two independent authors coded the posts’ content. Food and beverage items featured in posts were classified according to the NOVA food system classification. Marketing strategies were coded according to protocols from previous studies.Setting:Top three OFDS Instagram accounts in Brazil.Participants:Posts published in the period studied (n 304).Results:During the pandemic, the proportion of posts featuring at least one food item decreased from 71·6 % to 40·2 %, and the proportion of ultra-processed foods decreased from 57·6 % to 27·9 %. Before the pandemic, the most widely used marketing strategies were branding elements (80·7 %), product imagery (unbranded) (48·9 %) and partnerships/sponsorship (35·2 %). While during the pandemic, branding elements (62·2 %) continued to be the most applied, but were followed by the use of videos/graphics interchange format/boomerangs (34·1 %) and corporate social responsibility (31·7 %). The most frequent COVID-19 marketing strategies were ‘social responsibility in the pandemic’ (30·5 %), ‘combatting the pandemic’ (28·0 %) and ‘accelerating digitalisation’ (20·7 %).Conclusions:OFDS advertisements on a social media platform placed less emphasis on food items, but improved the nutritional quality of foods and beverages featured in posts. A COVID-washing approach was highlighted, especially through the use of social responsibility marketing during the pandemic.