In 2020, National Science Week events shifted online in response to Australian COVID-19 restrictions. Our research captures this rapid pivot from in-person to online science events, exploring experiences through audience and presenter questionnaires, and follow-up interviews. We examine characteristics of audiences for online science events, benefits and barriers of these events, and opportunities for online engagement. Key benefits were ease of attendance, new experiences enabled online, and greater control and flexibility. Lack of social interaction, technology issues, and audience reliability were identified as barriers. Our research suggests online events operate in a different sphere to in-person events and informs the delivery of engaging online experiences.