The COVID-19 pandemic has intensified global Sinophobia, leading to escalated verbal and physical assaults on the Chinese diaspora (Cabral, 2021; Reja, 2021; Salcedo, 2021; Than, 2021). Existing research indicates that online rhetoric, especially from prominent figures, can incite real-world racial animosity and aggression (Chan et al., 2016; Huang et al., 2022; Williams et al., 2020). This study first explores the overarching themes of online discourse centering on the COVID-19 news report in the United States, then focuses on the specific narratives that address China and the Chinese community to understand how Sinophobia is manifested and associated with the pandemic. Afterward, it delves into the temporal relationship between online Sinophobic sentiment and offline anti-Asian violence, accounting for the spill-over effect from targeted anti-Chinese antipathy to a broader anti-Asian hostility. Online Sinophobia is measured by comments under YouTube news videos about COVID-19 and Google searches for Sinophobic terms; offline Sinophobia is calculated by FBI hate crime statistics. This study identifies a bidirectional Granger causality between online and offline Sinophobia during the COVID-19 pandemic: anti-Asian hate crimes Granger-cause Google searches for Sinophobic terms, and conversely, these searches Granger-cause offline hate crimes, with a lag of two weeks. Additionally, it confirms a reinforcing dynamic between implicit and explicit online Sinophobia: the volume and intensity of anti-Chinese comments on YouTube news videos lead to increased Google searches for Sinophobic terms, and vice versa, with this effect observable over a ten-week lag. Furthermore, when accounting for confirmed infection cases, online Sinophobia is positively correlated with offline Sinophobia. These findings contribute to the existing literature on the relationship between online racist sentiment and real-life racial violence amidst this global crisis.