Grok 4.5 Drops Tomorrow, Crashes GPT-5.6's Launch Party 🚀

xAI will release Grok 4.5 to the public on July 9, according to a post by Elon Musk on July 8. Musk described the model as "Opus-class," saying it is "faster, more token-efficient and lower cost" than competing systems. The release positions xAI's latest flagship against OpenAI's GPT-5.6 family, which is also moving toward broad availability this week.

Grok 4.5 runs on xAI's 1.5 trillion-parameter V9 foundation, with Cursor coding data added in supplemental training. The model entered private beta at SpaceX and Tesla on June 28. Musk said at the time that early evaluations showed performance "close to or beyond Opus." He confirmed the public launch date on X, writing: "Based on strong positive feedback from customers in our beta test program, @xAI will make Grok 4.5 available to the public tomorrow."

OpenAI previewed its GPT-5.6 family in late June, restricting access to a small group of vetted partners. On Wednesday, the company said its GPT-5.6 Sol, Terra, and Luna models will launch publicly on Thursday, adding: "We're expanding preview access globally now." The expansion marks the first time GPT-5.6 variants will be available outside the limited preview program.

The timing revives a long-running rivalry between Musk and the company he helped establish. Musk co-founded OpenAI in 2015 and departed the board in 2018. In 2024, he filed suit against OpenAI and Sam Altman, alleging the organization had abandoned an early commitment to operate as a nonprofit. A jury dismissed the case in May as untimely.

With both companies opening access to their flagship models within the same week, attention shifts from preview benchmarks to real-world performance as developers and enterprises begin testing the competing systems.