GPT-4o is a multilingual, multimodal model that can process and generate text, images, and audio and represents a significant advancement over previous models like GPT-4 and GPT-3.5. GPT-4o is faster and more cost-effective, has improved performance in multiple areas, and natively supports voice-to-voice. GPT-4o's knowledge is limited to what was available up to October 2023. It has a context length of 128k tokens. The cost of training GPT-4 was more than $100 million, and it has 1 trillion parameters.