OpenAI's most advanced AI model is breaking free — and colliding with Elon Musk's latest Grok release

OpenAI’s latest and most powerful AI model is finally getting a public rollout, but not without Elon Musk stealing a bit of thunder.

OpenAI said it will roll out its new GPT-5.6 family of models more widely on Thursday, following the Trump administration’s request that the company stagger the model’s release.

A few hours after OpenAI’s announcement, which came late Tuesday California time, Musk said that SpaceXAI would launch its new Grok 4.5 model in the coming days.

OpenAI said last month that it had made a version of GPT-5.6 available to a limited set of partners who would provide feedback ahead of a general release.

That announcement followed a clash between Anthropic and the Trump administration, which put an export ban on the company’s Fable and Mythos models, citing the risk that they could be misused by adversaries for cyberattacks.

In response, Anthropic suspended the models.

Fable 5 was made available again last week.

OpenAI’s new GPT-5.6 will come in three flavors: Sol, Terra, and Luna.

Sol is the flagship model, which OpenAI says has stronger agentic abilities in coding, biology, and cybersecurity.

OpenAI said Terra is better “for everyday work,” while Luna is focused on speed and affordability.

Meanwhile, Musk said that Grok 4.5 is an “Opus-class model, but faster, more token-efficient and lower cost.” Opus is Anthropic’s family of advanced AI models.

The dueling announcements set the stage for another chapter in the rivalry between Musk and OpenAI CEO Sam Altman, who have just come out of a fierce legal battle.

Musk, who cofounded OpenAI but later stepped away, sued OpenAI and its leaders in 2024, accusing them of betraying an agreement that OpenAI would stay a nonprofit.

The case went to trial earlier this year, and Musk ultimately lost, with the jury ruling he had waited too long to file a lawsuit.

It’s also notable that both OpenAI and Musk are highlighting efficiency as a selling point for some of their new models.

As companies are becoming conscious of their token spend, labs are trying to make models faster and cheaper to run.

Google is also planning to release its next frontier model, Gemini 3.5 Pro, later this month, Business Insider previously reported.