By Addison Thompson 
The post-Twitter migration produced three very different outcomes. Meta’s Threads told investors it crossed 500 million monthly active users in the quarter ending June 2026. Bluesky, the decentralized app that drew the loudest exodus after Elon Musk’s 2024 election-season endorsement of Trump, has lost roughly half its active user base since its late-2024 peak. And Mastodon, the open-source network that got there first, just replaced the founder who built it with a professional nonprofit executive.
Threads: fastest-growing conversation app, by Meta’s own account
On Meta’s Q2 2026 earnings call, Mark Zuckerberg said Threads had “crossed 500 million monthly actives, making it the fastest-growing conversation app ever,” according to a transcript published by the Motley Fool. That figure comes with an obvious asset competitors lack: Threads launched pre-connected to Instagram’s more than 2 billion users, letting people bring their following and identity over in one tap rather than starting from zero. It has since built out its own algorithmic feed, trending topics and — unlike Instagram or Facebook proper — a limited ActivityPub integration that lets some Threads posts federate into the wider fediverse alongside Mastodon. That federation feature makes Threads an odd hybrid in this comparison: it is a centralized, ad-supported product built and controlled entirely by Meta, but it also plugs directly into the same open protocol underpinning Mastodon, letting a Mastodon user follow and reply to Threads accounts that have opted into federation without ever creating a Threads account themselves.
Bluesky: a shrinking app pivoting to a bigger protocol
Bluesky’s trajectory has gone the other way. According to Similarweb data reported by TechCrunch, Bluesky’s monthly active users fell from a late-2024 peak of 22.1 million to 10.7 million by the second quarter of 2026 — a decline of roughly 52%. June 2026 monthly actives were down 27.2% year-over-year to 10.4 million, and July daily actives were around 3 million, down 25.6% year-over-year. The app still counts nearly 46 million total registered accounts, but most of those people are not opening it regularly; its stickiness ratio (daily actives divided by monthly actives) sits around 29%, which TechCrunch notes is comparable to Threads despite the opposite growth direction.
Under CEO Toni Schneider, the company’s public strategy has shifted away from growing the flagship app and toward the underlying AT Protocol, the open standard Bluesky was built on. New efforts include an AI research tool called Attie and support for private, non-public data — both aimed at getting other apps and communities to build on the protocol rather than treating Bluesky-the-app as the only destination. The company continues to decline publishing official daily or monthly active-user figures, which is why outside estimates from analytics firms like Similarweb have become the main public benchmark for its trajectory.
Mastodon: a founder exit and a smaller, steadier network
Mastodon never approached Threads- or peak-Bluesky-scale usage, and it has settled at a smaller plateau: roughly 720,000-750,000 monthly active users spread across about 7,800-7,900 independently run servers, down from a peak of about 2.5 million monthly actives in late 2022 during the first wave of Twitter departures, per FOSS Force and The Register. Total registered accounts across the network exceed 10 million, though most are dormant.
The bigger story in 2025 was organizational. Founder Eugen Rochko stepped down as CEO on November 18, 2025, after more than nine years running the project, citing burnout: “The past two years especially have been overwhelming, and my mental and physical health have taken a dip,” he said, according to The Register. Rochko transferred the Mastodon trademark and remaining assets to the nonprofit structure the project had already begun building — a German gGmbH holding core assets since 2021, plus a US 501(c)(3) established in 2024 whose board includes Twitter co-founder Biz Stone. He received a one-time €1 million payment described as recognition for years of below-market compensation, and stayed on as a strategy and product advisor. Felix Hlatky, previously executive director at the Vienna-based nonprofit Solarys, took over as Mastodon’s first executive director. Rochko’s own explanation for the decline, cited by The Register, pointed to fatigue as much as competition: two years of overwhelming demands on a small team, running a network that grew faster than it could be professionally staffed, left the platform’s usage curve bending downward well before the leadership transition was announced.
Why the numbers moved so differently
The divergence comes down to distribution and durability. Threads inherited Instagram’s identity graph and Meta’s ad-tech and recommendation infrastructure, giving it both a running start and a reason for casual users to stay once curiosity wore off. Bluesky’s growth was driven largely by news-cycle spikes — the 2024 US election, periodic X controversies — that brought in waves of users who did not necessarily find a reason to return once the moment passed, which is consistent with the sharp post-peak decline. Mastodon’s federated, no-single-owner design was always going to cap mainstream growth by trading a slicker onboarding experience for independence from any one company, a trade its remaining users have largely made peace with.
What to watch next
Threads’ next test is whether Meta starts running ads against that user base at Instagram-level intensity without eroding what made it attractive as an X alternative. Bluesky’s is whether third-party apps built on AT Protocol can generate the kind of network effect the flagship app couldn’t sustain alone. And Mastodon’s is whether Hlatky’s more conventional nonprofit leadership can keep server operators funded and engaged without the founder who held the ecosystem together for a decade.
Sources
- Motley Fool: Meta Q2 2026 earnings call transcript
- TechCrunch: Bluesky’s active user base is shrinking
- FOSS Force: Rochko steps down as CEO, leaving Mastodon healthy
- The Register: Mastodon CEO steps down with €1M payout