xAI released Grok 4.5 on July 8, 2026, opening public access on grok.com and the X app the following day after a private beta with SpaceX and Tesla engineering teams. It is the company's first model built specifically for coding and agentic tasks, trained on xAI's 1.5-trillion-parameter V9 foundation using tens of thousands of Nvidia GB300 GPUs and supplemented with real developer session data from Cursor.
CEO Elon Musk described Grok 4.5 as "an Opus-class model, but faster, more token-efficient and lower cost," positioning it directly against Anthropic's flagship. The model ranks fourth on the Artificial Analysis Intelligence Index, ahead of every open-weight model and all Gemini models.
Pricing lands at $2 per million input tokens and $6 per million output tokens — cheaper than Claude Opus 4.8's $5/$25 but pricier than OpenAI's newly launched GPT-5.6 Luna at $1/$6. Grok 4.5 is available immediately via Grok Build, Cursor, and the API, though EU access remains blocked until mid-July.