ChatGPT becomes the fastest app in history to surpass 1 billion monthly users

OpenAI’s ChatGPT has surpassed 1 billion global monthly active users, making it the fastest application in history to reach the milestone, according to estimates from the market intelligence firm Sensor Tower.

The record was hit in May 2026, roughly three years after the chatbot launched in late 2022, surpassing the pace set by platforms that had previously defined explosive growth. Google Maps, TikTok, Instagram, and YouTube each took significantly longer to reach the same number. For context, TikTok took about six years to cross one billion monthly active users. ChatGPT did it in half the time.

An illustration photograph taken on February 20, 2025 shows ChatGPT app and website are displayed on a phone and laptop screens, in a residential property in Guildford, south of London. (Photo by Justin TALLIS / AFP)

The achievement reflects how rapidly generative AI has moved from a niche technology to a mainstream tool used by people across industries, age groups, and geographies — for everything from writing and coding to research, customer support, and creative work.

The milestone arrives at a particularly significant moment. Anthropic, OpenAI’s closest rival in the frontier AI space, filed confidentially for a US initial public offering on Monday. OpenAI is also reportedly preparing its own IPO filing in the coming weeks. The back-to-back moves suggest both companies are racing to capture public market momentum while investor appetite for AI remains strong.

OpenAI CEO, Sam Altman Claude’s growth rate outpaces ChatGPT’s

Although ChatGPT’s user numbers are higher, a significant detail in the data deserves attention. In the second quarter, Anthropic’s Claude had 56 million global monthly active app users. While this is a smaller user base than ChatGPT’s, Claude’s year-on-year monthly active user growth was about 640%, whereas ChatGPT grew by 62% during the same period.

Sensor Tower observed that US ChatGPT users who installed the Claude app in the first quarter of 2026 spent 5% less time on ChatGPT in the month following installation. This is compared to their average usage over the preceding eight months.

While this reduction is small, it indicates that users who try Claude tend to alter their habits, which could be significant on a larger scale.

For now, ChatGPT’s lead in absolute users is commanding. But the race for the next billion will be fought on very different terms than the first.

Similar read: Anthropic overtakes OpenAI as world’s most valuable AI startup with record $900bn valuation