conference paper accepted Marc Damie author Edwige Audrey Lucienne Cyffers author 20d4c299-977a-11ef-ae55-98b15ac64a57 ChLa department WWW: Web Conference Social network graphs are central to graph learning research, serving as standard benchmarks for algorithm evaluation. However, existing datasets focus mainly on mainstream social media platforms whose structures are shaped notably by algorithmic recommendations. This raises an important question: would alternative, decentralized social networks exhibit different properties? We address this by studying the Fediverse; a collection of decentralized social networks (such as Mastodon and Lemmy). These platforms differ fundamentally from for-profit social media, notably in decentralization and absence of recommendation algorithms, which may yield distinct graph structures. We introduce Fedivertex, a dataset of over 400 graphs from seven decentralized networks, collected weekly over six months. The dataset, released with a companion Python package to facilitate its use, supports research on temporal and structural aspects of decentralized social networks. In particular, we benchmark applications to decentralized machine learning and community detection. ACM2026Dubai eng 979840072307010.1145/3774904.3792868 8393-8396 M. Damie, E.A.L. Cyffers, in:, 2026 Proceedings of the ACM Web Conference 2026, ACM, n.d., pp. 8393–8396. Damie M, Cyffers EAL. Fedivertex: A graph dataset based on decentralized Social Media. 2026 Proceedings of the ACM Web Conference 2026. WWW: Web Conference, 8393–8396. Damie M, Cyffers EAL. Fedivertex: A graph dataset based on decentralized Social Media. In: <i>2026 Proceedings of the ACM Web Conference 2026</i>. ACM; :8393-8396. doi:<a href="https://doi.org/10.1145/3774904.3792868">10.1145/3774904.3792868</a> Damie, Marc, and Edwige Audrey Lucienne Cyffers. “Fedivertex: A Graph Dataset Based on Decentralized Social Media.” <i>2026 Proceedings of the ACM Web Conference 2026</i>, ACM, pp. 8393–96, doi:<a href="https://doi.org/10.1145/3774904.3792868">10.1145/3774904.3792868</a>. M. Damie and E. A. L. Cyffers, “Fedivertex: A graph dataset based on decentralized Social Media,” in <i>2026 Proceedings of the ACM Web Conference 2026</i>, Dubai, pp. 8393–8396. Damie, Marc, and Edwige Audrey Lucienne Cyffers. “Fedivertex: A Graph Dataset Based on Decentralized Social Media.” In <i>2026 Proceedings of the ACM Web Conference 2026</i>, 8393–96. ACM, n.d. <a href="https://doi.org/10.1145/3774904.3792868">https://doi.org/10.1145/3774904.3792868</a>. Damie, M., &#38; Cyffers, E. A. L. (n.d.). Fedivertex: A graph dataset based on decentralized Social Media. In <i>2026 Proceedings of the ACM Web Conference 2026</i> (pp. 8393–8396). Dubai: ACM. <a href="https://doi.org/10.1145/3774904.3792868">https://doi.org/10.1145/3774904.3792868</a> 219162026-05-24T22:01:32Z2026-06-03T05:40:18Z