Superhuman, the productivity software company formerly known as Grammarly, agreed to acquire GPTZero, a New York-based startup that detects AI-generated text. The companies announced the deal on 23 June 2026. Terms were not disclosed.
GPTZero will remain available as a standalone product and its detection tools will also run inside Superhuman Go, Superhuman's AI assistant that works across more than a million apps and websites. Superhuman said it plans to bring the features into Coda, its document product, later. The full GPTZero team of about 30 people, including co-founders Edward Tian and Alex Cui, is joining Superhuman, according to Business Insider as cited by BetaKit.
Superhuman chief executive Shishir Mehrotra said the company was building "an authenticity layer" and that GPTZero accelerated that plan.
What GPTZero built
Tian first built GPTZero as his senior thesis at Princeton University, and the company was founded in 2022 with Cui, a friend since high school, as chief technology officer. Both founders have roots in Toronto. It launched officially in January 2023.
Its tools now cover AI detection, hallucination detection, AI review, plagiarism checks and citation verification. AI Vision, launched in February 2026, flags AI-generated material as people browse, and Replay records how a document was written to show authorship. Its hallucination detector has been used to find citation errors in academic papers.
Tian told Business Insider that GPTZero had more than 19 million registered users and about $30 million in annual recurring revenue. BetaKit reported that it had 4 million users in 2024. Those figures come from the company and were not independently verified.
The company also runs IstheInternetAI.com, a site that tracks AI use online in real time. When BetaKit reported on the deal, the site estimated that 16% of internet content was AI-generated.
“As part of the Superhuman AI productivity platform, we’re building an authenticity layer, and GPTZero accelerates our vision.”
Why Superhuman is buying
Grammarly bought the email company Superhuman in 2025 and later took its name, repositioning itself as an AI productivity platform. Its products include Grammarly writing assistance, Coda collaborative documents, Superhuman Mail and the Go assistant. It says more than 40 million people, 50,000 organisations and 3,000 educational institutions use its products.
Superhuman already offered an AI detector, mainly used by students to check whether their writing looked machine-made. The company said different detectors can give conflicting results and that "two AI detectors are better than one." Mehrotra said the combined company would bring "the most trusted writing tool and the most trusted AI detector into one platform."
Tian wrote that joining Superhuman would give GPTZero more resources and customer insight, and let it build features it could not manage alone, such as AI detection inside email inboxes.
Superhuman is based in the San Francisco Bay Area and has about 1,500 employees, according to LinkedIn data cited by BetaKit. It opened an office in Vancouver in 2019, and its co-founders Max Lytvyn, Dmytro Lider and Alex Shevchenko have ties to Canada.
The founders and the funding
GPTZero raised $13.5 million in total, according to TechCrunch. Its $3.5 million seed round was led by Uncork Capital. In June 2024 it raised a $10 million Series A led by Footwork co-founder Nikhil Basu Trivedi, with Reach Capital, Jack Altman's Alt Capital and Neo also investing. Tian told TechCrunch in 2024 that the company was profitable.
The acquisition price was not made public, and neither company said whether Superhuman would pay in cash, stock or both.
Questions for users
The deal places a widely used AI detector inside a company whose main products help people write with AI. Superhuman also faces a class action filed earlier in 2026 over an "expert review" feature that produced editing suggestions based on well-known authors and academics without their consent, BetaKit reported.
For now, Superhuman told Coda users that their experience would stay the same, and GPTZero's existing customers keep access to the standalone service.
Superhuman scheduled a virtual event for 25 June to explain the deal to its community. The companies did not give a date for completing the acquisition.
