As of my last knowledge update in October 2023, OpenAI's latest flagship model is **GPT-4**, which was officially released in March 2023. GPT-4 is a large multimodal model, meaning it can process both text and image inputs (though its image understanding capabilities were initially available through a limited set of partners, such as Be My Eyes). It represents a significant improvement over its predecessor, GPT-3.5, in terms of accuracy, reasoning, creativity, and contextual understanding.

If OpenAI has released a newer model after GPT-4, I recommend checking OpenAI's official website or blog for the latest updates.
