Many new users have said their decision to join Bluesky was driven by Elon Musk, who heavily backed Trump’s election campaign and intends to remain involved in the new administration.
Threads, Meta’s competitor to X, has also continued to expand.
“People are both disgusted and afraid of Elon Musk and what Twitter has become,” said Cory Johnson, Chief Market Strategist at Epistrophy Capital Research.
“Users are fleeing X, and Bluesky and Threads are the beneficiaries.”
It is not the first time that apps trying to rival X with a similar format for text posts have had a flurry of new sign-ups.
A decentralised network called Mastodon added hundreds of thousands of users after it popped up in the wake of Elon Musk’s Twitter takeover.
Bluesky and Threads both had a spike in users in 2023 as Mr Musk began to implement changes to the platform.
This week, the British news outlet the Guardian announced it will no longer post on X, saying the US election underlined its concerns that Musk had been able to use X to “shape political discourse”.
As Thursday’s outage unfolded, Bluesky staff tried to make light of the situation, with one developer joking, external: “Btw — Today will get interesting! If the site goes down, maybe grab a soda, pet the kitty. We’ll hit it with a wrench as fast as we can.”
Additional reporting by Liv McMahon