Grok 4.5 and GPT-5.6 Enter Limited Access; Same-Day Launch Unconfirmed

Both xAI's (now SpaceXAI) "Grok 4.5" and OpenAI's "GPT-5.6" have entered limited-access phases, and rumors of a same-day public launch are spreading, but neither has been officially confirmed. By late June 2026 the two companies had begun rolling out their new models in succession, marking a new stage in the frontier-model race. As of July, however, neither has reached general availability.