Grok 4 AI Model Launched by Elon Musk's xAI Alongside the World’s Most Expensive AI Subscription Plan

Grok 4 artificial intelligence (AI) model was released by xAI on Monday. The new AI model was introduced by xAI developers and company owner Elon Musk in a live stream on X (formerly known as Twitter). The company claimed that the new large language model (LLM) comes with a significantly improved reasoning ability and better performance across multiple subject areas. Grok 4 was introduced alongside Grok Heavy, a multi-agent system which collaborates on problems and generates higher quality outputs. Apart from that, xAI also introduced the most expensive AI subscription so far.

Grok 4 and SuperGrok Heavy Subscription Announced

In a post on X, the official xAI handle hosted a 48-minute-long live stream where Musk and xAI developers detailed various aspects of the Grok 4 AI model. One particular area where the new model outperforms its predecessor is academic knowledge. “Grok 4 is better than a PhD level in every subject, no exception,” Musk said.

Grok 4 performance on the Humanity's Last Exam benchmark
Photo Credit: xAI

The team announcing the AI model also showcased Grok 4's performance across several benchmarks, including Humanity's Last Exam. It is a set of 2,500 questions designed specifically to test AI systems across a wide range of subjects. xAI claimed that Grok 4 scored 25.4 percent on the test, outperforming frontier models such as Google's Gemini 2.5 Pro (21.6 percent) and OpenAI's o3-high (21 percent).

Additionally, Musk claimed that with tool use, Grok Heavy scored as high as 44.4 percent on the test, beating OpenAI's o3 with Deep Research, which scored 26 percent, and Gemini 2.5 Pro with tools, which achieved 26.9 percent.

The company did not reveal a lot about the Grok Heavy system, apart from introducing it as a multi-agent environment where multiple specialised agents can work together to find different solutions to a problem, and then compare them to find the best solution among them all. It appears to be similar to the open-source algorithm that Sakana AI released earlier this month.

Finally, Musk and xAI also introduced the most expensive consumer-focused AI subscription so far. Dubbed SuperGrok Heavy, the subscription costs a whopping $300 (roughly Rs. 25,700) a month. Aimed at the power users of Grok, the subscription offers higher rate limits and early access to new features, such as Grok Heavy.