This is one of Vox's Future Perfect predictions for 2023; they give it a 60% probability.

In its brief history, the research group OpenAI has released four large language models capable of producing intelligible text under the name “GPT,” or Generative Pre-trained Transformer. The first iteration came out in summer 2018. Then in early 2019, they unveiled GPT-2; in summer 2020 came GPT-3, and as part of the very high-profile ChatGPT product they revealed in late November 2022, they announced they had created GPT-3.5. The question then naturally arises: When is GPT-4 coming?

Impressionistically, I find GPT-3.5 outputs much more convincing than GPT-3 ones, but OpenAI did not judge the advance significant enough for the name GPT-4. The release schedule also seems to be slowing down somewhat. But the rumor mill points in the opposite direction, with the New York Times’s Kevin Roose reporting murmurs that GPT-4 will come out in 2023, and TechCrunch’s Kyle Wiggers more evasively suggesting “perhaps as soon as 2023.”

I’m inclined to give the rumor mill some weight, which is why I think GPT-4 in 2023 is more likely than not, but I’m not confident at all.

(Vox)

Resolves according to Vox Future Perfect's judgment at the end of the year.