<p>Health communication shapes how individuals interpret, trust and act on information about prevention, vaccination and emerging health threats. Yet, evidence remains limited on which characteristics of quality health information most influence decision-making, and whether these preferences are consistent across global contexts. Here we conducted an online cross-sectional survey across 30 countries (<i>N</i> = 31,000 adults) to explore perceptions of quality health information. We then analysed these questions by country, national economic standing, governmental characteristics of the nation and individual demographics to identify patterns of perception and information access globally. Our findings showed high levels of digital health literacy in upper-middle-income and low-middle-income countries. Across countries, clarity, accessibility and source identification emerged as the most valued features of quality health information. Trust in healthcare providers was consistently higher than in government or community sources. Messages attributed to providers elicited stronger agreement with statements of concern, appeal and behavioural intent than identical messages attributed to governments or community organizations. While most respondents preferred mixed words-and-images formats, acceptance of artificial intelligence-generated health content varied widely. Collectively, these findings illustrate the global consistency of certain quality cues, such as transparency and simplicity, while highlighting variation in the perceived credibility of institutional versus interpersonal sources. Improving global health communication will require aligning message design with public expectations for clarity, openness and professional endorsement, particularly as artificial intelligence and digital media transform how people encounter and evaluate health information.</p>