We may not yet know exactly what Elon Musk’s takeover of Twitter means for the platform, but one Twitter alternative is already booming as a result of the news. Mastodon, the open-source social media service which bills itself as the “largest decentralized social network on the internet,” has been “exploding” since Musk’s acquisition, according to its founder.

News of Twitter’s buyout has rattled Twitter employees and users, as Musk has indicated he plans to take a much more hands-off approach to content moderation. As is often the case when Twitter makes a controversial change, some users have threatened to leave the platform, while critics have pushed #RIPTWITTER to trend.

In this case, at least some disgruntled users are apparently turning to Mastodon as a potential alternative. Hours after the Twitter acquisition was announced, Mastodon said it saw “an influx of approx. 41,287 users.” Of those, about 30,000 were new users, Mastodon founder Eugen Rochko wrote in a blog post.

“Funnily enough one of the reasons I started looking into the decentralized social media space in 2016, which ultimately led me to go on to create Mastodon, were rumours that Twitter, the platform I’d been a daily user of for years at that point, might get sold to another controversial billionaire,” he wrote. “Among, of course, other reasons such as all the terrible product decisions Twitter had been making at that time. And now, it has finally come to pass, and for the same reasons masses of people are coming to Mastodon.”

Mastodon’s official iOS and Android apps are also seeing an uptick in users, according to data provided by analytics firm Sensor Tower. The apps have been downloaded roughly 5,000 times “or nearly 10% of its lifetime total” downloads since Monday, according to the firm. The app is currently ranked No. 32 on the App Store charts for social media apps.

It’s not the first time Mastodon has benefited from issues at Twitter. The company was briefly popular in 2017, following outrage over Twitter’s decision to remove user handles from the character limit for @-replies (back when Twitter changed its product so infrequently even mundane changes were fodder for mass outrage). Mastodon saw another uptick in 2019, when users in India were angry over moderation policies. 

While Mastodon has been in the spotlight as a potentially viable Twitter alternative in the past, it has yet to reach the mainstream. But its current popularity comes at a moment when Twitter is also exploring how it could become an open-sourced protocol — much like Mastodon.

Unlike Twitter, Mastodon is not a single, centralized service. Though the interface looks similar to Twitter — it has a 500-character limit but otherwise will be mostly recognizable to Twitter users — it runs on an open-source protocol. Groups of users are free to create and maintain their own “instances” with their own rules around membership, moderation and other key policies. Users are also able to take their followers with them between instances.

Mastodon operates its own instances, mastodon.social and mastodon.online, but those are apparently overloaded, according to Rochko, who suggests that new users sign up via the official apps and join other communities on the service. And, because it’s open source, Mastodon makes its code available on GitHub, an idea Musk has also endorsed with regards to Twitter’s algorithms.

But all that also comes with extra complexity for new users who may not easily understand Mastodon’s unique structure or how it works. But those who stick around long enough may see some significant new features. Rochko said that end-to-end encrypted messaging is in the works, as well as “an exciting groups functionality.”