Three AI assistants reached a billion users faster than any social app
Meta AI reached a billion monthly users 20 months after it launched, Google's Gemini took about 41 months, and ChatGPT reached a billion weekly users in about 44, by the companies' own counts. TikTok, the fastest of the big social apps, took 49 months, while Instagram took 92 and Facebook 103.
The two fastest assistants started inside products that already had billions of users. Meta AI sits in WhatsApp, Instagram and Facebook, and Gemini is built into Android phones and Google's apps. ChatGPT is a standalone app, and OpenAI counts people who use it each week, a stricter measure than the monthly figures the others report.
The other assistants are much smaller. Similarweb estimates Claude's mobile app had about 157 million monthly users in August, up from 9 million a year earlier, and Anthropic does not publish its own count. SpaceX's IPO filing puts xAI's Grok at 117 million monthly users, and Microsoft says its Copilot products together have 150 million. Twitter never reached a billion; its reported monthly users peaked around 336 million in 2018.
Company counts are hard to check from the outside. Sensor Tower, which measures every app the same way, estimated Gemini at 662 million monthly users in May, against the 900 million Google announced that month, and put ChatGPT at about 1.1 billion.
What's next
Google reports Gemini's users at its earnings calls, and OpenAI updates ChatGPT's at product events. Meta has not given a Meta AI total since May 2025, so it is unclear how much further it has grown.
How we counted: each line starts at the product's first reported user count and is measured from its launch date, including Bard, now Gemini, on March 21, 2023, Claude's app on July 11, 2023, TikTok's international app in September 2017 and Facebook on Feb. 4, 2004. ChatGPT figures are weekly users; all others are monthly users or, for Facebook and Instagram's early years, company-announced active users. Claude figures are Similarweb estimates for its mobile apps, and the Copilot figure combines Microsoft's business and consumer products. Sources: OpenAI, Google, Meta, Microsoft, the SpaceX S-1, Twitter and TikTok filings, Sensor Tower and Similarweb.