OpenAI CEO Sam Altman compared the company’s recent surge in popularity to the early days of Y Combinator, following a record spike in users driven by a new AI image generation feature.

In a post on X (formerly Twitter), Altman wrote:

“Lol I feel like a YC founder in ‘build in public’ mode again.”

The remark follows a whirlwind week for OpenAI, which released its new image generation tool for ChatGPT on March 25. The feature quickly gained traction, with users flooding social media with AI-generated images inspired by Studio Ghibli’s signature animation style.

The response was overwhelming—so much so that Altman revealed OpenAI saw its biggest-ever spike in users after the feature’s launch.

“The ChatGPT launch 26 months ago was one of the craziest viral moments I’d ever seen, and we added one million users in five days. We added one million users in the last hour,” Altman wrote on March 31.

OpenAI Struggles to Keep Up With Demand

However, the explosion in activity has caused significant strain on OpenAI’s infrastructure. Just two days after the feature launched, Altman admitted that OpenAI’s GPUs were struggling to keep up with the demand.

“It’s super fun seeing people love images in ChatGPT. But our GPUs are melting,” Altman posted on March 28.

To stabilize operations, OpenAI temporarily introduced rate limits while working on optimizing performance. By Tuesday, Altman said the company was “getting things under control”, but warned users to expect occasional delays and service disruptions.

“We are working as fast as we can to really get stuff humming; if anyone has GPU capacity in 100k chunks we can get ASAP, please call!” he added in a separate post on April 1.

OpenAI’s Soaring Valuation

Amid this surge in demand, OpenAI continues to grow at an unprecedented pace. On Monday, the company announced it had raised $40 billion at a $300 billion valuation—nearly double its worth from October 2024, when it raised $6.6 billion at a $157 billion valuation.

Altman, who previously led startup accelerator Y Combinator, has long been at the center of Silicon Valley’s most significant tech revolutions. Before OpenAI, he founded Loopt, a social networking startup that was among Y Combinator’s earliest-backed companies in 2005. Loopt was later acquired by Green Dot for over $43 million.

After serving as president of Y Combinator from 2014 to 2019, Altman shifted his focus entirely to OpenAI—a move that has since placed him at the helm of one of the most influential AI companies in the world.

As OpenAI continues to push AI capabilities forward, the challenge remains: Can it scale fast enough to keep up with its explosive user growth?