Abstract Amid the COVID-19 pandemic, TikTok, an emerging social media platform, has created an information hub to provide users with engaging and authoritative COVID-19 information. This study investigates the video format, type and content of the COVID-19 TikTok videos, and how those video attributes are related to quantitative indicators of user engagement, including numbers of views, likes, comments and shares. A content analysis examined 331 videos from official accounts featured in the COVID-19 information hub. As of 5 May 2020, the videos received 907 930 000 views, 29 640 000 likes, 168 880 comments and 781 862 shares. About one in three videos had subtitles, which were positively related to the number of shares. Almost every video included a hashtag, and a higher number of hashtags was related to more likes. Video types included acting, animated infographic, documentary, news, oral speech, pictorial slideshow and TikTok dance. Dance videos had the most shares. Video themes included anti-stigma/anti-rumor, disease knowledge, encouragement, personal precautions, recognition, societal crisis management and work report. Videos conveying alarm/concern emotions, COVID-19 susceptibility and severity, precaution response efficacy had higher user engagement. Public health agencies should be aware of the opportunity of TikTok in health communication and create audience-centered risk communication to engage and inform community members.