Emoji and visual complexity in health information design: A moderated serial mediation model

•Individuals responded differently to the use or non-use of emoji in health information.•An automated content analysis and a 2x3 between-subject experimental design were performed.•Emoji leads to higher levels of perceived enjoyment (PE), perceived interactivity (PI), and social media engagement (SME).•Emoji have a serial mediation effect on SME through PE and PI.•Visual complexity of information moderates the serial mediation effect of emoji on SME through PE and PI. Social media is a valuable tool that enables public health organizations to communicate effectively. To enhance the reach of health communication on social media, scholars have proposed that emoji be used to convey scientific information. The current study explored the influence of emoji on the effectiveness of health communication on social media. Automated content analysis revealed that the presence of emoji in online health information resulted in higher levels of social media engagement (SME) than the absence of emoji did. Additionally, a 2 (emoji: present versus absent) × 3 (visual complexity of information design: low versus medium versus high) online experiments revealed that the presence of emoji in health information sequentially increased perceived enjoyment and perceived interactivity, thereby promoting SME. However, this effect is influenced by the visual complexity of health information designs. The presence of emoji is only effective in increasing SME with health information presented using a design with low or medium visual complexity. This study provides theoretical and practical insights into visual health communication and health information design.