ChatGPT smashes through a billion monthly users — Image: Jernej Furman

OpenAI’s ChatGPT has crossed one billion global monthly active app users, becoming the fastest app ever to reach the milestone, according to estimates from market intelligence firm Sensor Tower.

The record comes amid growing competition between Anthropic and OpenAI for dominance in the rapidly expanding artificial intelligence market.

Here are some details:

ChatGPT reached a billion monthly active users in May, roughly three years after launch, surpassing the pace set by apps including Google Maps, TikTok, Instagram and YouTube, Sensor Tower said.
The firm said US ChatGPT users who installed Anthropic’s Claude app in the first quarter of 2026 spent 5% less time on ChatGPT one month after installation, compared with their average usage in the prior eight months.
Anthropic confidentially filed for a US initial public offering on Monday, while OpenAI is also reportedly preparing to file for an IPO in the coming weeks.
As of the second quarter to date, Claude had 56 million global monthly active app users, while its year-over-year MAU growth of about 640% significantly outpaced ChatGPT’s 62% growth, according to Sensor Tower. — Harshita Mary Varghese, (c) 2026 Reuters