With the rise of misinformation, there is a great need for scalable educational interventions supporting students’ abilities to determine the trustworthiness of digital news. We address this challenge in our study by developing an online intervention tool based on tutorials in civic online reasoning that aims to teach adolescents how to critically assess online information comprising text, videos and images. Our findings from an online intervention with 209 upper secondary students highlight how observational learning and feedback support their ability to read laterally and improve their performance in determining the credibility of digital news and social media posts.