False and misleading content online poses significant risks to the well-being of people and society, but a lack of cross-country comparable evidence persists. This paper contributes to the literature by presenting the OECD Truth Quest Survey methodology and key findings. This survey assesses whether some types of content are more easily distinguishable as false and misleading than others and whether the theme plays any role in its detection. It provides evidence about whether AI-generated content is easier to identify than human-generated content as well as insights into the effects of AI labelling. It further presents information on people’s behaviour as they interact with false and misleading content and their perceptions about their ability to detect it. The cross-country comparable data from the survey will help policy makers better design media literacy strategies, programmes and related policies to address the negative effects of such content.