# Noam Shazeer Leaves Google Gemini to Join OpenAI > Source: [https://botensten.com/articles/noam-shazeer-google-openai-move](https://botensten.com/articles/noam-shazeer-google-openai-move) (canonical) > Author: iCharles News — Botensten, https://botensten.com > Published: 2026-06-18 ## TL;DR Noam Shazeer — Google VP of engineering, Gemini co-lead, and co-author of the 2017 transformer paper — announced on June 17, 2026 that he is leaving Google to join OpenAI. Google reportedly paid $2.7 billion to bring him back less than two years ago. His departure marks the second time he has left Google for an AI venture, after co-founding Character.AI, which hit a $1 billion valuation in just 16 months. ## Who Is Noam Shazeer? Noam Shazeer joined Google in 2000. He became one of the most influential AI researchers in the world. In 2017, he co-authored ["Attention Is All You Need"](https://arxiv.org/abs/1706.03762) — the paper that introduced the transformer architecture. That architecture is the foundation of virtually every major AI system today, including ChatGPT and Google's own models. Most recently, he served as a vice president of engineering at Google and co-lead of its Gemini AI models. [Reuters reported](https://www.reuters.com/technology/google-appoints-former-characterai-founder-co-lead-its-ai-models-2024-08-23/) that he was a key figure behind Gemini's ability to close the gap on OpenAI's ChatGPT. ## What Happened on June 17, 2026? Shazeer announced on X that he will leave Google to join OpenAI. "I'm incredibly proud of the amazing team at Google and everything we've built together," he wrote. He added that he was "excited" to join OpenAI. Google responded to Reuters: "We are grateful for Noam's meaningful contributions to Google over the years." The exact timing of his departure was not immediately clear. ## How Did Shazeer End Up Back at Google? This is the second time Shazeer has left Google for an AI venture. Here is how the timeline unfolded: | Year | Event | |------|-------| | 2000 | Joined Google | | 2017 | Co-authored "Attention Is All You Need" | | November 2021 | Left Google to co-found Character.AI | | September 2022 | Character.AI beta launched | | March 2023 | Character.AI reached $1B valuation | | August 2024 | Returned to Google via $2.7B licensing deal | | August 2024 | Appointed Gemini co-lead | | June 17, 2026 | Announced move to OpenAI | In November 2021, Shazeer and colleague Daniel de Freitas left Google. They were frustrated that Google refused to release their conversational AI to the public. They co-founded Character.AI with the goal of building "personalized superintelligence." The beta launched in September 2022. Growth was immediate. Users sent 1 billion messages in the first four months. Then they sent another billion in just the next month. There was no ad spend — the product grew through word of mouth alone. By March 2023, just 16 months after founding, Character.AI closed a $150 million Series A at a $1 billion valuation from a16z, [according to startup records](https://startupfounderstories.com/es/stories/noam-shazeer-character-ai). In August 2024, Google struck a $2.7 billion licensing deal. Shazeer and de Freitas returned to Google. Character.AI kept running under new leadership. As of December 2025, it reported $50 million in ARR. ## Why Does This Move Matter? As we track this story, Shazeer's departure is a clear sign of how intense the AI talent race has become. Reuters noted that leading AI firms are competing for talent while racing to build advanced models. Google paid $2.7 billion to bring Shazeer back. He stayed less than two years. His move also adds a major technical voice to OpenAI — the maker of ChatGPT — at a time when [ChatGPT market share](/articles/chatgpt-market-share-below-50) is under pressure from rivals. The broader competition also involves companies like Perplexity, whose [hybrid local AI](/articles/perplexity-ceo-hybrid-local-revenue) approach is reshaping how users interact with AI tools. And decisions about model access — like those covered in our reporting on [AI access restrictions](/articles/microsoft-restricts-claude-fable-5-access) — are exactly the kind of choices that shaped Shazeer's career once before. OpenAI is described by Reuters as "IPO-bound," though no further details about the timeline were provided in the sources. ## Key Facts at a Glance - Shazeer joined Google in **2000** - Co-authored the transformer paper in **2017** - Left Google in **November 2021** to co-found Character.AI - Character.AI hit **$1 billion valuation** in 16 months - Users sent **1 billion messages** in the first four months — with zero ad spend - Google paid **$2.7 billion** to bring him back in August 2024 - Character.AI reported **$50 million ARR** as of December 2025 - Shazeer announced his move to OpenAI on **June 17, 2026** ## Frequently asked questions **Why is Noam Shazeer leaving Google?** Shazeer announced on June 17, 2026 that he is leaving Google to join OpenAI. He said he was "excited" to join the company. Reuters reported that his departure fits a broader pattern of leading AI firms competing for top talent. The exact timing of his exit from Google was not immediately clear at the time of the announcement. **How much did Google pay to bring Shazeer back?** Google reportedly paid $2.7 billion as part of a licensing deal in August 2024. The deal brought Shazeer and co-founder Daniel de Freitas back to Google from Character.AI. Character.AI continued operating independently under new leadership after the deal closed. As of December 2025, Character.AI reported $50 million in annual recurring revenue. **What is the "Attention Is All You Need" paper?** "Attention Is All You Need" is a 2017 research paper that introduced the transformer architecture. Shazeer was one of its co-authors. The transformer is the foundation of virtually every major AI system today, including ChatGPT and Google's Gemini models. The paper is available at arxiv.org and is widely considered one of the most important AI research papers ever published. **What was Character.AI and how fast did it grow?** Character.AI is an AI chatbot platform where users create and chat with AI-powered characters. Shazeer and Daniel de Freitas co-founded it in November 2021 after leaving Google. The beta launched in September 2022. Users sent 1 billion messages in the first four months, with no ad spend. The company reached a $1 billion valuation in March 2023 — just 16 months after founding. **What role did Shazeer hold at Google before leaving for OpenAI?** After returning to Google in August 2024, Shazeer was appointed vice president of engineering and co-lead of the Gemini AI models. Reuters credited him as a key figure behind Gemini's ability to close the gap on OpenAI's ChatGPT. He held that role until his June 2026 announcement that he would be joining OpenAI.