For the first time since GPT-2 in 2019, OpenAI is releasing new open-weight large language models. It's a major milestone for a company that has increasingly been accused of forgoing its original stated mission of "ensuring artificial general intelligence benefits all of humanity.

It’s the first such models it’s launched in over five years, as pressure in the US grows to respond to China’s dominance in open models.

OpenAI is releasing a pair of open and freely available artificial intelligence models that can mimic the human process of reasoning, months after China’s DeepSeek gained global attention with its own open AI software.