It's not exactly a shock to hear this news, but now it's truly official. In a Twitter post, Microsoft's Yusuf Mehdi, the company's Corporate Vice President and Consumer Chief Marketing Officer, has confirmed that its Bing Chat chatbot AI, which launched several weeks ago, is indeed running on GPT-4, the newly announced version of ChatGPT developed by OpenAI. The message is further confirmed by a post on the Bing blog site.


Previously, Microsoft would only say that Bing Chat was using its own Prometheus model and the "new, next-generation OpenAI large language model".

Other than that, Microsoft is only saying that GPT-4 for Bing Chat has been "customized for search". There's no other info yet, including when Microsoft might add the image-text combo feature that was revealed by OpenAI today.