This project aims to assess the extent of online disinformation problem (“fake news”) in Western Europe compared to the US: Although scholarship on disinformation has increased substantially since 2016, there is a lack of work comparing these findings with the situation in other Western democracies outside the US. The main goal of this project is to understand which contextual and individual factors foster the dissemination and consumption of online disinformation and with what effects. More specifically, which actors spread false information, how is it consumed and perceived, and which societal groups are most susceptible to being affected by it. Switching the perspective, we are also interested in the factors enabling the resilience of countries facing the problem of online disinformation. The project entails two datasets to analyze the producers' as well as consumers' side: First, a representative online survey in six countries (Belgium (Flanders): n = 1,063; France: n = 1,255; Germany: n = 1,019; Switzerland (German-speaking regions): n = 1,251; UK: n = 1,380; US: n = 1,038) that incorporates an experimental part (N = 7,006). To investigate the interaction with disinformation, we created stimuli that consist of false claims covering the three issues Covid-19, climate change, and migration - all designed as a social media post, varying in reporting style elements and amount of popularity cues (number of likes, shares, comments). Key variables and concepts that we measured prior to the stimuli are: Socio-demographics, issue salience, political attitude, news consumption, social media usage, exposure to politicians' posts, and media trust. Key variables and concepts that we measured after the experimental treatment are: Emotional reaction, agreement with false claim, willingness to interact with the false post (like, share, comment, no reaction) and motivations for that interaction, personality traits, political interest and orientation, disinformation concerns and exposure, and (mis-)information literacy. Second, a manual quantitative content analysis of Facebook-posts published by alternative media in five countries (N = 1,661): France, n = 350; Germany, n = 350; Switzerland, n = 261; UK, n = 350; US, n = 350. This dataset focuses on different disinformation types and styles which we grouped in disinformation categories (i.e., fabricated falsehoods, false connections, ideological biases) and genre-typical features (i.e., conspiracy rhetoric, call for skepticism, use of pseudo-experts, clickbait journalism, emotionality, sensationalism, counter-positioning, critizism of various targets, and political topics).