The release of gpt-oss-120b and gpt-oss-20b "open-weight language models" comes as the ChatGPT-maker is under pressure to share inner workings of its software in the spirit of its origin as a nonprofit.

"Going back to when we started in 2015, OpenAI's mission is to ensure AGI (Artificial General Intelligence) that benefits all of humanity," said OpenAI chief executive Sam Altman.

An open-weight model, in the context of generative AI, is one in which the trained parameters are made public, enabling users to fine-tune it.

Meta touts its open-source approach to AI, and Chinese AI startup DeepSeek rattled the industry with its low-cost, high-performance model boasting an open weight approach that allows users to customize the technology.

"This is the first time that we're releasing an open-weight model in language in a long time, and it's really incredible," OpenAI co-founder and president Greg Brockman said during a briefing with journalists.

The new, text-only models deliver strong performance at low cost, according to OpenAI, which said they are suited for AI jobs like searching the internet or executing computer code, and are designed to be easy to run on local computer systems.

"We are quite hopeful that this release will enable new kinds of research and the creation of new kinds of products," Altman said.

OpenAI said it is working with partners including French telecommunications giant Orange and cloud-based data platform Snowflake on real-world uses of the models.

The open-weight models have been tuned to thwart being used for malicious purposes, according to OpenAI.

Altman early this year said his company had been "on the wrong side of history" when it came to being open about how its technology works.

He later announced that OpenAI will continue to be run as a nonprofit, abandoning a contested plan to convert into a for-profit organization.

The structural issue had become a point of contention, with major investors pushing for better returns.

That plan faced strong criticism from AI safety activists and co-founder Elon Musk, who sued the company he left in 2018, claiming the proposal violated its founding philosophy.

In the revised plan, OpenAI's money-making arm will be open to generate profits but will remain under the nonprofit board's supervision.