Mozilla exits the fediverse and will shutter its Mastodon server in December

Mozilla is exiting the fediverse. Though the concept of the open social web, also known as the fediverse, has been picking up momentum ever since Meta last year introduced its first-ever federated app, Instagram Threads, Firefox maker Mozilla on Tuesday announced it would be ending its experiment in running a server on the fediverse. The server, Mozilla.social, today connects users with the Mastodon social network, an open source rival to Twitter/X. It will be shut down on December 17.

In the meantime, users will be able to download their data or migrate their account to another Mastodon instance, if they choose.

The latter takes advantage of the account portability offered by the open social web. Unlike on centralized platforms, users don't have to abandon an account and lose both their content and followers if they don't like how a server is being run or the rules it has in place. Instead, they can opt to relocate to another Mastodon server at any time or even run their own. The same applies to when a server's owner chooses to shut down their instance, as Mozilla is now doing.

Mozilla.social was a small instance, having only 270 active users at the time of Tuesday's announcement. By comparison, the most popular Mastodon instance, Mastodon.social, has over 247,500 monthly active users.

Mozilla had telegraphed its plans to scale back on its fediverse investments earlier this year after the CEO stepped down. At the time, Mozilla board member Laura Chambers took over the job as the interim CEO of Mozilla Corporation through the end of 2024. Shortly after the change in leadership, Mozilla said it would refocus its product strategy around Firefox and AI and significantly scale back or even shutter other efforts. Among those products affected by the pullback were its VPN, Relay, and Online Footprint Scrubber, in addition to its Mastodon instance, the company said at the time. Meanwhile, its virtual world Hubs was shut down.

The redirection of Mozilla's efforts came after its flagship product, the Firefox web browser, spent years losing market share. That left room for other competitors, like the startup Arc, to take hold in the alternative browser market.

Months prior to this change in strategy, Mozilla had been touting the fediverse's potential, but under Chambers, the company said that a more "modest approach" to the fediverse would have allowed it to participate with "greater agility." In an internal memo, Mozilla signaled that going forward, a "much smaller team" would participate in the Mastodon ecosystem. However, it didn't say at the time that the Mozilla.social instance would shut down, adding that it would continue to bring small experiments to those who participated on its instance.

Mozilla shared its plans to shut down the server in a post on Mastodon's social network, calling it a "hard decision."

"Thank you for being part of the Mozilla.social community and providing feedback during our closed beta. You can continue to use Mozilla.social until December 17," the post noted before providing links to help users export data and migrate accounts.

In addition, the Mozilla-backed startup Mammoth, makers of a third-party Mastodon app, announced it was migrating its instance over to Mastodon hosting provider Mastohost. However, Mammoth co-founder Bart Decrem tells TechCrunch this move was totally unrelated to Mozilla's broader decision to leave the fediverse.

"Mozilla signaled that it was focusing its efforts on Firefox and AI some months ago, so this does not come as a surprise," Decrem said. "I’m excited about the promise of ActivityPub and the fediverse, and Mastodon is an important part of that, but this is a good reminder that we have a lot of work ahead."