How Microsoft’s Bing Chatbot Came to Be—and Where It’s Going Next

Jordi Ribas hasn’t taken a day off since last September. That month, the Microsoft search and AI chief got the keys to GPT-4, a then secret version of OpenAI’s text-generation technology that now powers ChatGPT. As Ribas had with GPT-4’s predecessors, the Barcelona native wrote in Spanish and Catalan to test the AI’s knowledge of cities like his hometown and nearby Manresa. When quizzed about history, churches, and museums, its responses hit the mark. Then he asked GPT-4 to solve an electronics problem about the current flowing through a circuit. The bot nailed it. “That’s when we had that ‘aha’ moment,” Ribas says.

Ribas asked some of Microsoft’s brightest minds to probe further. In October, they showed him a prototype of a search tool the company calls Prometheus, which combines the general knowledge and problem-solving abilities of GPT-4 and similar language models with the Microsoft Bing search engine. Ribas again challenged the system in his native languages, posing Prometheus complex problems like vacation planning. Once again, he came away impressed. Ribas’ team hasn’t let up since. Prometheus became the foundation for Bing’s new chatbot interface, which launched in February. Since then, millions of people spanning 169 countries have used it for over 100 million conversations.

It hasn’t gone perfectly. Some users held court with Bing chat for hours, exploring conversational paths that led to unhinged responses; Microsoft responded by instituting usage limits. Bing chat’s answers occasionally are misleading or outdated, and the service, like other chatbots, can be annoyingly slow to respond. Critics, including some of Microsoft’s own employees, warn of potential harms such as AI-crafted misinformation, and some have called for a pause in further development of systems like Bing chat. “The implementation in the real world of OpenAI models should be slowed down until all of us, including OpenAI and Microsoft, better study and mitigate the vulnerabilities,” says Jim Dempsey, an internet policy scholar at Stanford University researching AI safety risks.

Microsoft isn’t commenting on those pleas, but Ribas and others working on the revamped Bing have no plans to stop development, having already worked through weekends and fall, winter, and spring holidays so far. “Things are not slowing down. If anything, I would say things are probably speeding up,” says Yusuf Mehdi, who oversees marketing for Bing.

With just over 100 million daily Bing users, compared to well over 1 billion using Google search, Microsoft has thrown itself headlong into a rare opportunity to reimagine what web search can be. That has involved junking some of the 48-year-old company’s usual protocol. Corporate vice presidents such as Ribas attended meetings for Bing chat’s development every day, including weekends, to make decisions faster. Policy and legal teams were brought in more often than is usual during product development. 

The project is in some ways a belated realization of the idea, dating from Bing’s 2009 launch, that it should provide a “decision engine,” not just a list of links. At the time, Microsoft’s current CEO, Satya Nadella, ran the online services division. The company has tried other chatbots over the years, including recent tests in Asia, but none of the experiments sunk in right with testers or executives, in part because they used language models less sophisticated than GPT-4. “The technology just wasn’t ready to do the things that we were trying to do,” Mehdi says.

Executives such as Ribas consider Bing’s new chat mode a success—one that has driven hundreds of thousands of new users to Bing, shown a payoff for the reported $13 billion the company invested in OpenAI, and demonstrated the giant’s nimbleness at a time when recession fears have increased Wall Street scrutiny of management. “We took the big-company scale and expertise but operated like a startup,” says Sarah Bird, who leads ethics and safety for AI technologies at Microsoft. Microsoft shares have risen 12 percent since Bing chat’s introduction, well more than Google parent Alphabet, Amazon, Apple, and the S&P 500 market index.