OpenAI is finally releasing an open weight model

Sam Altman took to X (formerly Twitter) to announce that OpenAI plans to release an open-weight model in the coming months. This is different from OpenAI's previous approach, where access to models like GPT-3.5 and GPT-4 has been restricted through APIs. So far, users could only use these models via OpenAI’s interface or by integrating API keys into their applications, meaning the model itself stayed secret and proprietary.

However, open-weight models are different. These are models where the pretrained parameters (the “weights” that define how the model responds) are openly shared with the public. Developers and researchers can download them, run them locally, fine-tune them for specific use cases, or plug them into custom applications. However, just because the weights are open doesn’t mean everything else is. Training code, datasets, and detailed logs might still remain proprietary or undisclosed, so sometimes it might not be fully open-source as well.

Companies like Meta and Mistral have already released powerful models like Llama and Mixtral, and newer players like DeepSeek, Alibaba, and Baichuan are pushing out competitive models that can rival them. or even outperform closed models in specific use cases. From academic researchers to indie devs, many have started preferring open-weight models because they offer more flexibility, transparency, and cost control.

To support the rollout, OpenAI is planning a series of developer events across San Francisco, Europe, and the APAC region. These sessions are meant to be interactive, letting early users experiment with prototypes and customization options, and more importantly, provide feedback.

In his X post, Altman said that OpenAI will evaluate the model according to its preparedness framework, just like any other model, and that the company will do extra work, knowing that this model will be openly released and will be modified.

If you're a developer interested in being part of that loop, you can sign up using this link to join OpenAI’s upcoming developer sessions.