It has long been assumed that social media would equalize election campaigning by providing cheap means of communication for smaller parties who lack a strong mass media presence. Yet given the increased political importance of social media, parties with more professional staff and resources could also gain the upper hand in online campaigns. So far, knowledge of the development of online campaigning in a rapidly changing political and technological landscape remains limited, as only few studies have taken a longitudinal and cross-country approach so far. This paper conducts a comprehensive analysis of more than 12,000 unique candidates from all 28 European Union (EU) member states in the 2014 and 2019 European Parliament (EP) elections. We theorize and empirically assess how party size and parties’ EU position relate to the presence, the activity and the salience of the EU among EP candidates on Twitter (now X). In the 2019 election, parties with a bigger national vote share and Europhile parties were more likely to be present and use Twitter more frequently to tweet about the EU. Overall, the findings point to a ’normalization’ of online election campaigning and a further convergence of first and second-order elections.