OpenAI co-founder Greg Brockman estimates 1.5 billion people have tried ChatGPT

Roughly 1 to 1.5 billion people have given ChatGPT a spin at some point. Most of them didn’t stick around. OpenAI co-founder and president Greg Brockman shared that estimate during a podcast appearance on September 8, offering a rare glimpse at the gap between ChatGPT’s cultural penetration and its ability to keep users coming back. The platform currently boasts over 1 billion weekly active users, which sounds massive until you realize it means hundreds of millions of people tried the product and walked away. The billion-user milestone and what it hides ChatGPT hit roughly 900 million weekly active users around early 2026, then crossed the 1 billion weekly active threshold by July 2026. Monthly users had already surpassed 1 billion around May or June, according to third-party tracking data. If 1.5 billion people have tried the product and roughly 1 billion use it weekly, that leaves something like 500 million people who sampled ChatGPT and decided it wasn’t for them. Brockman attributed the retention gap to misconceptions people form during their first interactions. Put simply: people try ChatGPT once, get a mediocre answer to a poorly worded prompt, and conclude the whole thing is...