Background: Digital media is ubiquitous in adolescents’ lives and provides many opportunities to engage with health information. However, there is an increased risk of engaging with inaccurate or biased health information on the internet, resulting in poor health-related behaviours. As such, adolescents would benefit from improving their digital health literacy (DHL). There are limited education tools in DHL that are interactive and relatable for adolescents. A co-design approach can incorporate adolescents’ perspectives in designing an education tool to ensure its relevance.

Aims: This study aimed to determine the effectiveness of the co-design approach in creating an educational resource designed to improve adolescents’ DHL.

Methods: Three workshops were conducted with adolescents (12–17 years) to explore their DHL habits and education needs, evaluate an existing DHL educational app, co-design new storylines to better meet their needs and beta test the expanded resource. Data was collected through creation of storyboards, annotated posters and worksheets. Data analysis of these artefacts was undertaken through content analysis to identify themes and sub-themes.

Results: Forty-four participants attended two co-design workshops. Participants preferred using video-based social media and considered using artificial intelligence (AI) tools for extracting online health information. They designed storylines involving health topics such as dietary supplements, fitness and mental health. Storylines focused on identifying trustworthy online health information sources and dealing with concerns regarding scams, social media influencers and misinformation conveyed by parents. Eight participants who attended the beta-testing workshop positively evaluated the app as engaging and relatable.

Discussion: This study clarified the DHL educational needs of adolescents. In particular, it demonstrated the need to include other media literacies, the use of AI tools and interactions with family in the resource to maximise relevance to adolescents.

Conclusion: The co-design methodology was useful for understanding adolescents’ DHL lived experiences and developing an engaging educational resource to help them navigate and appraise online health information.