"What a year," Meta CEO and Facebook founder Mark Zuckerberg said Wednesday on Threads in announcing the platform had reached the threshold.
Threads, which hit app stores on July 5 last year, is a spin-off of Instagram and is intended to be a rival to X, formerly known as Twitter, after that platform alienated many users and advertisers following Elon Musk's purchase in 2022.
Threads was rushed out after Musk threatened to limit the amount of posts on X for non-subscribers.
This was the latest in a long line of chaotic announcements by the mercurial Tesla founder and Zuckerberg tried to seize the moment.
Promoted through their Instagram accounts, more than 100 million people downloaded Threads within a week of its launch in 100 countries, though the EU had to wait until December over regulatory concerns.
The push from Instagram helped Threads become the fastest downloaded app ever, crushing the previous record held by AI sensation ChatGPT.
The initial enthusiasm waned however, and Threads has more gradually grown usage, with a big help from the Instagram crossover and exiles turned off by Musk-owned X.
Threads chief Adam Mosseri said he hoped the platform would become more independent from Instagram over time and intends to open it to advertisers in the not so distant future.
Getting bigger than Musk’s X "will take some time, but I will consider it a failure if we don't get there," Mosseri told the Platformer news website.
Threads has drawn flack for Meta's decision to downplay news and politics in an effort to become a more friendly site than X at the risk of dulling engagement.
"A year after launch, we know what Threads isn't, but we don't know what it is," said Emarketer principal analyst Jasmine Enberg.
"The lack of a unique identity is one of its biggest hurdles to achieving real staying power," she added.
Now privately owned by Musk, X no longer releases industry metrics; the company insists that its user base is growing and more engaged than on other platforms.
"Threads was launched during a time when X was struggling, but since then, X has been surprisingly resilient," said Debra Aho Williamson, chief analyst at Sonata Insights, a research firm.
"Sports and political discussion are still very active on X, and considering that we have the Olympics, Euro 2024 and the U.S. presidential election this year (among other major events), X will probably continue to attract users," she added.