Sam Altman said that OpenAI's new GPT-oss, comprising a 120b and 20b version, is the "best and most usable open model in the world."

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.