Elon Musk's xAI has launched Grok 4.5 into private beta at SpaceX and Tesla. The new 1.5-trillion-parameter model, built on the V9 foundation, began internal testing on June 28, 2026.
Early evaluations suggest Grok 4.5's performance approaches or exceeds Anthropic's Opus. The model represents a 50% parameter increase from its predecessor, Grok 4.4.
Grok 4.5 incorporates training data from Cursor, the popular AI code editor. This provides the model with extensive exposure to real-world coding workflows and debugging patterns.
The strategic choice to test at SpaceX and Tesla is deliberate. Both companies operate at the intersection of hardware engineering, software systems, and real-time decision-making, offering xAI access to proprietary operational data most competitors cannot replicate.
xAI plans an aggressive release schedule, aiming to launch new models trained at SpaceX every month through the end of 2026. The rapid scaling from 1 trillion to 1.5 trillion parameters in roughly one month signals intense competitive pressure in the AI sector.