The Bebras Challenge is organized in more than 70 countries worldwide. It aims to foster pupils’ interest and passion for informatics and computational thinking. Although the Bebras Challenge is by its nature an online activity, most countries had a decline in participation numbers compared to non-pandemic years. Some countries recorded larger relative declines than others, certain countries even recorded increases. In order to investigate this issue, a comprehensive study, applying quantitative and qualitative methods, was conducted. Based on reported participation data, an interactive online graphic was created in which the reach (participation per thousand inhabitants) of the Bebras Challenge in individual countries or groups of countries in the respective years can be compared with each other. Following an online research regarding homeschooling during the Bebras weeks in different countries, an online survey among 40 Bebras representatives worldwide delivered important key data, such as main reasons for an incline or decline of participation numbers or which measures have been taken to hold the challenge during the pandemic. This was accompanied by qualitative interviews with selected Bebras representatives. The results of this study could help organizers of national and international school activities to respond more effectively to possible future adverse situations.