Decentralized Social Media Rises as Twitter Melts Down

Mastodon is just the start—here comes the Fediverse

4 min read
A laptop on a table in a coffee shop. It's open, and the Mastodon server is loaded in a web browser.

Mastodon’s rise has led the Fediverse into the spotlight.

Matthew S. Smith / IEEE Spectrum

Is the future of social media decentralized? That question might’ve felt absurd a few years ago, but the Fediverse is challenging long-held assumptions about how social media should work.

The Fediverse, unlike the social networks that rose to dominance over the last two decades, is a decentralized collection of servers that communicate over an open protocol. The idea isn’t new, but it’s gained traction as centralized social networks like Twitter, Facebook, and Tiktok find themselves mired in controversy.

“You basically lose your entire social graph to go [to another social network], which is a superhigh wall,” says Tim Chambers, principal and cofounder of Dewey Digital and administrator of the Mastodon server “However, when things become sufficiently chaotic on platforms,

as Twitter is seeing now, that is a force strong enough to incite such migrations.”

What is the Fediverse?

The Fediverse reverses this trend with an open, freely available protocol called ActivityPub. In 2018 the World Wide Web Consortium (W3C) defined the ActivityPub protocol, which defines client-to-server and server-to-server interactions to build a decentralized framework for social media. It based this on similar, earlier protocols such as, created by the open-source advocate and Open Earth director of open tech Evan Prodromou.

Mastodon, a text-based social network similar to Twitter, is the most popular example of ActivityPub in action. Users can post text, share images, and follow others. But Mastodon, unlike Twitter, is not hosted as a singular service but instead a collection of independent servers that communicate through ActivityPub. Joining Mastodon means joining a server with its own community and code of conduct. Users can interact with users on other servers, but each of their accounts is hosted on the server they choose.

A screen capture of, a Mastodon server instance connected to the Fediverse through the ActivityPub is one of several thousand Mastodon servers that communicate over the ActivityPub

Chambers has observed this community focus in the movement of users from Twitter. “There is early evidence that immediately after the Musk takeover entire communities began to migrate over to Mastodon in relatively sizable cohorts,” says Chambers. For example, Twitter CEO Elon Musk’s decision to ban journalists who reported on a Twitter account that tracked the location of his private jet caused many to abandon the service., a Mastodon server for working and retired journalists, was founded on 4 November 2022, and now has over 1,000 active users.

The Fediverse’s connected but independent servers give users more control. Everyone has the option to join the server they think best, and moving to a new server is relatively simple. Servers can also block other servers, providing more power to respond against harassment or objectionable content.

This power is also a barrier, however, as users must put more thought into how they engage with the Fediverse. Its open nature also allows anyone to create third-party clients, giving users yet another decision to make.

A screen capture showing three examples of how Ivory, an iPhone app used to access Mastodon, is used on Apple's iPhone.Ivory is one of many third-party clients that hopes to improve Mastodon’s user experience. Ivory

This can be intimidating, but Chambers believes developers will eventually solve these problems. “Other issues with Mastodon, such as users learning the onboarding process, and learning how this network is different than Twitter, I think those are less of a barrier than some do,” he says. “Most of those issues are being solved by new clients for mobile and desktop apps such as Ivory or Mona. The entire Mastodon app space is evolving very quickly to solve the user experience issue.”

And Mastodon is hardly the Fediverse’s only offering. There’s also PeerTube, a decentralized video-sharing system; PixelFed, a similarly open-servered image-sharing service; Friendica, a more Facebook-like social media system; and Funkwhale, a community-driven music platform.

How popular is Mastodon?

Mastodon, however, remains the marquee platform, at least for the time being. The latest waves of publicity for Mastodon have brought in more users, too—a lot more users.Mastodon hit 1 million active users in November of 2022, and the number of active monthly users on Fediverse-connected platforms has more than quadrupled since November of 2022. This surge sparked fears that commercial interests might follow the trend, a fear seemingly made real by Mask Network’s purchase of, the world’s second-largest Mastodon server. The platform is decentralized, but what if companies purchase the most popular servers?

“I think the design of the network makes it hard to execute some of the more abusive business models we see in siloed social media.”
—Evan Prodromou, Open Earth

Not everyone shares this concern, however. “I’m not opposed to commercial ventures in the Fediverse. I think the design of the network makes it hard to execute some of the more abusive business models we see in siloed social media,” says Prodromou. “But I really appreciate how aware and active Fediverse users are.” Time has so far proven Prodromou’s lack of concern warranted, as the purchase of wasn’t followed by the purchase of other Mastodon servers.

Instead, most companies looking to support decentralized social media are adding support for ActivityPub or, in some cases, building new platforms for a decentralized future. Meta is rumored to be working on its own decentralized social network, code-named P92, which is said to include ActivityPub support. WordPress and Flipboard have announced features that integrate with the Fediverse. Mozilla, meanwhile, announced in December that it would “stand up and test a publicly accessible instance in the Fediverse” in its Mozilla.Social network.

Not everyone is embracing ActivityPub, however. Bluesky, a decentralized social-media startup supported by Twitter cofounder and former CEO Jack Dorsey (who sits on Bluesky’s board), is building its own decentralized service from scratch. The company defended its approach in a Twitter post on 6 April of last year.

Bluesky’s stance hints at a potential conflict between decentralized protocols. Though not yet public, Bluesky is listed on Apple’s App Store as an invite-only private beta. Prodromou, however, has strong words for any organization looking to enter social media with a new decentralized social media protocol. “I’m not interested in any protocol besides ActivityPub,” he says. “Anyone working on brand new protocols in 2023 should stop immediately. They are going to do more harm than good.”

Update 24 March 2023: This story was updated to reflect the fact that the Mozilla organization did not develop the Fediverse extension that was recently rolled out.

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