TikTok algorithms: Which topics are the most popular

Internet platform recommender systems play a crucial role in the everyday lives of many people. Regardless of whether they use a search engine, social media, or video platforms: Algorithms decide which content is shown to users, in which order, and in which context. Despite the immense importance of these systems for the digital public sphere, it is difficult for users, policymakers, researchers, and civil society to understand how these systems actually work.

Using the TikTok platform as an example, we have analyzed what drives the recommender, what content is shown, and how user interactions influence it. For getting answers to these questions, we programmed an automated bot that watched about 220,000 videos in the period from the beginning of June to the end of August 2022 and collected information, especially hashtags, about these videos. A first visualization shows which TikTok topics are presented to new users and the connections that lead from one topic to other, often related topics.

The larger the circle (representing a hashtag), the more often it appeared in the data set. Clicking on a circle shows the connections to other hashtags. The thickness of the line connecting two circles indicates how often the hashtags appear together.