Comparing User Activity on X and Mastodon
Shiori Hironaka, Mitsuo Yoshida, Kazuyuki Shudo
TL;DR
This paper investigates how user activity differs between a centralized platform (X) and a decentralized Mastodon instance within Japan. It combines data from Twitter's 1% Japanese stream and Mastodon local timelines, aggregates posts by user, and applies a Biterm Topic Model with $K=30$ to derive cross-platform topic distributions. Key findings include a higher share of replies on Twitter, more consistent engagement on the Mastodon instance mstdn.jp, and distinct topic preferences by server, illustrating the impact of federation structure on activity patterns. The study provides a cross-platform analytic framework for the Fediverse and offers insights for platform design and policy in decentralized social networks, with implications for researchers studying user behavior across heterogeneous ecosystems.
Abstract
The "Fediverse", a federation of decentralized social media servers, has emerged after a decade in which centralized platforms like X (formerly Twitter) have dominated the landscape. The structure of a federation should affect user activity, as a user selects a server to access the Fediverse and posts are distributed along the structure. This paper reports on the differences in user activity between Twitter and Mastodon, a prominent example of decentralized social media. The target of the analysis is Japanese posts because both Twitter and Mastodon are actively used especially in Japan. Our findings include a larger number of replies on Twitter, more consistent user engagement on mstdn.jp, and different topic preferences on each server.