Elon Musk's xAI has officially launched Grok 4, its latest AI model, during a livestream event early morning Thursday(UTC). The model is positioned as the world's most powerful AI, with advanced reasoning and real-world problem-solving capabilities, surpassing models from OpenAI, Google, and Anthropic.
“Grok 4 is a postgrad-level in everything,” Musk said during the hour-long live broadcast. “With respect to academic questions, Grok 4 is better than PhD level in every subject, no exceptions. At times, it may lack common sense, and it has not yet invented new technologies or discovered new physics, but that is just a matter of time.”
xAI launched two models: Grok 4 and Grok 4 Heavy — the latter being the company’s “multi-agent version” that offers increased performance. Musk claimed that Grok 4 Heavy spawns multiple agents to work on a problem simultaneously, and then they all compare their work “like a study group” to find the best answer.
xAI says that Grok 4 shows frontier-level performance on several benchmarks, including Humanity’s Last Exam — a challenging test measuring AI’s ability to answer thousands of crowdsourced questions on subjects like math, humanities, and natural science. According to xAI, Grok 4 scored 25.4% on Humanity’s Last Exam without “tools,” outperforming Google’s Gemini 2.5 Pro, which scored 21.6%, and OpenAI’s o3 (high), which scored 21%.
The company says that Grok 4 Heavy, with “tools,” was able to achieve a score of 44.4%, outperforming Gemini 2.5 Pro with tools, which scored 26.9%.
The nonprofit Arc Prize says that Grok achieves a new state-of-the-art score on its ARC-AGI-2 test — another difficult benchmark that consists of puzzle-like problems where an AI has to identify visual patterns — scoring 16.2%. That’s nearly twice the score of the next best commercial AI model, Claude Opus 4.
During Thursday’s livestream, Musk said that, according to his “biological neural net,” AI systems should be optimized “to be maximally truth seeking” and encouraged “to be truthful, honorable, good things—like the values you want to instill in a child that would ultimately grow up to be incredibly powerful.”
Alongside Grok 4 and Grok 4 Heavy, xAI launched its most expensive AI subscription plan yet, a $300-per-month subscription called SuperGrok Heavy. Subscribers to the plan will get an early preview to Grok 4 Heavy, as well as early access to new features. The plan is similar to ultra-premium tiers offered by OpenAI, Google, and Anthropic, but xAI now offers the most expensive subscription among major AI providers.
Grok 4 is available through multiple platforms, including the xAI apps, grok.com, and the X platform.