Elon Musk’s Twitter takeover last October and the associated chaos drove millions of people into the arms of niche open source microblogging platform Mastodon. Overnight, a shaggy extinct mammal became associated with a buzzy network touted as the independent future of social media.

Companies and politicians joined up. Twitter users put Mastodon usernames in their handles and trumpeted their migration. The new traffic knocked many Mastodon instances, or servers, offline. In less than two months, Mastodon’s monthly active users climbed from 380,000 to more than 2.5 million. But not everyone stuck around. 

Mastodon’s active monthly user count dropped to 1.4 million by late January. It now has nearly half a million fewer total registered users than at the start of the year. Many newcomers have complained that Mastodon is hard to use. Some have returned to the devilish bird they knew: Twitter.

After a decade of Big Tech dominating social media, the idea of a small, alternative, and open source platform like Mastodon growing into a truly mainstream challenger was alluring to some. The decentralized platform operates very differently from services like Facebook, Instagram, and Twitter and demands volunteers take on the job of sustaining and moderating servers. That’s because Mastodon is part of the Fediverse, a network of servers running interoperable open source software.

Thanks to dedicated admins, many instances survived the flood of sign-ups and came back stronger. But Mastodon never was, and never will be, Twitter. For some, that’s what makes Mastodon valuable. To others, it’s a barrier. But the Twitter migration showed that Mastodon can adapt—and quickly. 

“The biggest lesson of what happened is that Mastodon and the rest of the Fediverse can scale. This was a big question,” says Robert Gehl, a professor of communication and media studies at York University in Canada. He has studied Mastodon and says it’s enjoyed peaks of interest followed by slumps before. But that pattern can still add momentum. “Each time, a percentage of the wave sticks,” Gehl says. “You get people converting to it.” 

During Mastodon’s Musk bump, admins worked hard to get servers swamped by new users back online. They crowdfunded money to pay for increased hosting bills and updated their policies on content moderation.