Cybersecurity & Tech

What on Earth Is the Fediverse?

Kiernan Christ
Monday, May 9, 2022, 11:02 AM

It isn’t a social media site but a decentralized collection of servers that represents an entirely different way of organizing social media.

3D visualization of the proposed Fediverse logo. (Eukombos,; CC BY-SA 4.0,

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The past six years have seen no shortage of critiques lobbed at social media companies from all angles. These concerns mean that users may be looking for alternative services, based on their particular grievances with mainstream social media. Various substitutes gain attention, and some users consider or even migrate to new platforms. But the Fediverse often ducks under the radar. It isn’t a social media site but a decentralized collection of servers that represents an entirely different way of organizing social media. Although the Fediverse remains small relative to the number of users on mainstream platforms, those interested in the future of the internet and regulation should be aware of the Fediverse: how it works, who uses it and why it’s important.

The Fediverse is a network of interconnected servers, which communicate with each other based on decentralized networking protocols. These servers can be used for any number of different services, such as social media or file hosting. The most popular services are Mastodon, PeerTube (video hosting, like YouTube), and Pleroma (social networking and microblogging similar to Mastodon).

To understand how the Fediverse functions, two concepts are key: the software platforms of which the Fediverse consists, and the communication protocols used by those software platforms.

Using a Fediverse service isn’t like signing up to use Twitter or Facebook, where you create an account and use it to communicate only with other users of that platform. Fediverse services are not single websites, but pieces of open-source software that allow anyone to run their own social networking service using that particular software’s functions. Imagine, for instance, running your own Facebook—you keep all the functionality and features that Facebook’s software incorporates, but you determine who’s allowed on your Facebook and what rules they have to follow. Servers on the Fediverse, called “instances,” federate with other instances so the user experience is that of an integrated social network. This leads to a decentralized distribution of authority and responsibility across the network: Mastodon, for example, provides the microblogging software, but those hosting instances retain complete authority over how they wish their particular community to function. While this structure provides users and instance owners with greater control, it also means that individual instances must manage their own operations and security. For example, individual instances are responsible for mitigating distributed denial of service (DDoS) attacks themselves—without centralized governance, there’s no centralized protection. 

While there are catch-all instances for users simply interested in joining the network, many instances are catered to a specific audience. This curated list provides examples of what kinds of instances constitute the Fediverse: communities for radio amateurs, Esperanto speakers and programmers. 

Communication protocols describe the rules by which information can be transmitted between users and servers within a network. A number of different protocols are in use across the Fediverse, including ActivityPub and diaspora. Shared protocols allow users of different software platforms to communicate with each other. For example, a Mastodon instance and a non-Mastodon instance can communicate when both use the ActivityPub protocol. Having an account on Friendica doesn’t limit you to communicating only with other Friendica users—because Friendica is part of the Fediverse, users of other services like Mastodon or Pleroma can communicate with you directly without needing to share a platform. This would be similar to scrolling an Instagram feed, but Facebook posts from friends and from Twitter users one follows also appear integrated into that platform.

It is difficult to estimate the exact number of Fediverse users because of the decentralization of the service—there is no single party monitoring the size of the network nor is there an ultimate authority who oversees the network. Estimates, by third parties, indicate a growth from about 600,000 users in early 2019 to 4.5 million in late 2021. 

Just as important as the number of users of the Fediverse is the composition of that user base. Anyone can use the Fediverse, but there are a few different audiences that have embraced it. Each of these audiences, for different reasons, had concerns about or found it difficult to remain on mainstream social media platforms. Their adoption of federation highlights some features that differentiate the Fediverse from mainstream tech. 

Early coverage of Mastodon focused on its ability to provide a more curated space free from the “toxic behavior” present on larger sites like Twitter. In 2017, federated services were described as appealing to “queer and trans” people who “fled Twitter due to harassment.” This movement was due in part to the increased power of moderation tools to allow users to curate their own online experiences. For example, Mastodon introduced “defederation” in 2017, which allows instances to block all content from another instance considered problematic or harmful. Instances can also choose to only federate with a small number of other instances vetted for, for example, friendliness to LGBTQ users. While mainstream social media platforms allow individual users to block others, the Fediverse allows for community-level engagement with or disengagement from other communities. 

The Fediverse is also popular among users concerned about online privacy. While the Fediverse as such lacks any centralized privacy policy, users choose the server on which they wish to open an account, selecting the person who will be in charge of their data. A federated service does not preclude the use of trackers on a particular instance. Proponents argue, however, that despite these risks, the choice of instance allows users to select against instances that would require users to give up control of their data. Instead of picking an instance, users can also choose to open and operate their own servers. Technical experience is required. One needs to buy a domain name (a URL), configure a server by determining where content like pictures will be hosted, and potentially purchase DDoS protection. It’s complicated, but all of these steps mean that server owners can retain complete control over data on their servers while remaining fully connected to the Fediverse.

Users who cannot remain on mainstream platforms because of content moderation also view the Fediverse as an alternative. For example, Gab, a microblogging site popular among far-right users, joined the Fediverse in 2019. Gab described the success of this shift as making them “unstoppable,” arguing that they “can never again be taken down as a whole ever again.” By joining the Fediverse, they could circumvent “Google’s and Apple’s ban on their own app from their app stores, since offering Mastodon’s client-side API would allow any existing Mastodon app to be used to access Gab.” 

Many Fediverse users reacted negatively, asking Mastodon to prohibit Gab from using the software or otherwise joining the Fediverse. However, as Mastodon founder Eugen Rochko explained to The Verge, it’s “not actually possible to do anything platform-wide because it’s decentralized.” Mastodon simply doesn’t “have the control.” Despite the lack of centralized moderation, most of the largest instances on the Fediverse chose to defederate from Gab, isolating it from other parts of the network. Rochko even encouraged instance owners to “be vigilant and domain-block” Gab. 

Right-wing influencers on mainstream social media services have also promoted the Fediverse as a censorship-free alternative. For example, Luke Smith, a YouTuber with more than 135,000 subscribers described as having a history of “promoting far-right political ideology,” has enthusiastically promoted the Fediverse. In the face of censorship, Smith says that Fediverse users can simply “go to another VPS provider or start your own service”—the Fediverse “ultimately cannot be censored.” If you sign up to one particular Mastodon instance, for example, and then are banned for breaking that instance’s rules, you may still continue to use Mastodon and interact with other instances by signing up to another instance or setting up your own server. 

The Fediverse represents just one possibility for alternative social media services adopted by those deplatformed from the mainstream. The lack of centralized authority determining acceptable content on instances, unlike alt-tech services such as Parler or Bitchute, allows extremists even greater freedom to maintain their own spaces while remaining connected to a larger network.

The history of the internet contains example after example of failed social media startups. But the Fediverse isn’t just a new social media platform. Instead, it’s an entirely different way of organizing social media. Those interested in social and political dynamics on the internet should be aware of the Fediverse and how it operates, because it could potentially change the way users interact with each other and with service providers. 

Unlike other alt-tech platforms, the Fediverse wasn’t created to serve a particular audience or for an explicitly political reason. The diversified user base may be a contributing factor to future success because the Fediverse isn’t explicitly associated with a particular subculture or political ideology. The issues many Americans have with mainstream social media—distrust, harassment, censorship, lack of privacy—have potential solutions or mitigations on the Fediverse.

Policymakers should be aware of the Fediverse, even though it currently has a much smaller user base than any mainstream social media company. Regulations developed to deal with the negative consequences of Big Tech may be ineffective or incompatible with decentralized services. Treating technology companies as public utilities or mandating transparency reporting are solutions built on an understanding of the internet as made up of centralized, hierarchical, distinct services—nothing like the Fediverse. Those seeking to understand the landscape of the internet should be aware of what movement toward the Fediverse represents and how the decentralized, open-source nature of that network challenges conventional approaches to moderation and community.

Kiernan Christ is a student in the School of Foreign Service at Georgetown University. She is an editor-in-chief of the Georgetown Journal of International Affairs.

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