As AI-generated content storms the internet, productivity company Superhuman is acquiring GPTZero, an AI detection startup cofounded by Edward Tian and Alex Cui in 2023.
GPTZero, which Tian, now 26, built as a senior at Princeton, went viral after its launch and has since evolved to include additional tools to detect hallucinations and AI-generated content in social media feeds.
The companies declined to share the financial terms of the deal. GPTZero is valued at over $88 million, according to PitchBook, and it's backed by investors like Uncork Capital, Neo, Footwork, and Jack Altman.
GPTZero has grown rapidly since its launch three years ago, Tian said. He added that it surpassed 19 million registered users and $30 million in annual recurring revenue.
As part of the acquisition, Tian and Cui will join Superhuman to lead a team focused on authenticity. GPTZero's 30 employees will also join Superhuman, Superhuman CEO Shishir Mehrotra said.
"When you're buying a business like this, the people come first," Mehrotra said of GPTZero's cofounders.
Superhuman was formerly known as Grammarly and changed its name after acquiring Superhuman, an email app popular across Silicon Valley and among venture capitalists.
It now offers a variety of productivity tools, and its acquisition of GPTZero aims to strengthen its existing authenticity tools, including its Grammarly AI detector and an Authorship product that helps writers verify their work.
GPTZero will soon be accessible within Superhuman Go, an AI assistant that operates across websites and apps. GPTZero will also continue to operate as a stand-alone product.
Deciphering which content is and isn't AI-generated is especially critical in education, Mehrotra said, and demand is also coming from professional fields such as consulting, recruiting, and journalism. Education accounts for roughly a third of the more than $700 million in annual revenue of Superhuman's flagship writing assistant Grammarly, he said, while professional users generate the remainder.
"GPTZero started with the mission of preserving what's human," Tian said. "Now we need to preserve critical thinking."
GPTZero marks Superhuman's fourth major acquisition, Mehrotra said. Previously, the company acquired the productivity assistant Coda, the email app Superhuman (for which it is now named), and the AI spreadsheet tool Rows.
Mehrotra said Superhuman's acquisition strategy was influenced by his tenure at Google, which expanded from a single product into a broader suite. He said he sees Superhuman's 40 million daily users as a "trampoline" to help acquired companies scale more quickly.
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Geoff Weiss is a senior reporter on Business Insider’s tech team, where he writes about AI startups and Y Combinator, the intersection of AI and the media industry, and workplace dynamics within top AI labs and chip companies.Previously, Geoff was on the media desk, covering YouTube and Netflix, and themes like the intersection of Hollywood and the creator economy. His work on Netflix’s video podcasting ambitions and Mr Beast’s lessons for Hollywood won second and first prize, respectively, at the 2025 LA Press Club Awards.Prior to joining Business Insider, Geoff was the senior editor of Tubefilter and a staff writer at Entrepreneur. He graduated from New York University with a degree in English Literature.He can be reached at [email protected], on Signal @geoffweiss.25, and on LinkedIn. Have a tip? Use a personal email address and a nonwork device; here's our guide to sharing information securely.Selected stories:Nvidia crushed its quarter — and CEO Jensen Huang said in a leaked all-hands that 'the market did not appreciate it'Nvidia will foot the bill for Trump's new visa fees. Here's what CEO Jensen Huang told staff.Massive AI salaries and RTO are fueling a real estate boom in San Francisco: 'It's going to rain money'The AI talent wars are ricocheting across startups. Here's how they're competing with Big Tech.
