Grok 4 and Grok 4 Heavy are advanced AI models developed by Elon Musk’s company, xAI, launched in July 2025. Both represent significant leaps in AI capabilities, with Grok 4 touted as having intelligence exceeding PhD-level expertise across all subjects, and Grok 4 Heavy being a more powerful multi-agent version designed for complex problem-solving.
| Feature | Grok 4 | Grok 4 Heavy |
| Architecture | Single-agent AI model | Multi-agent system with up to 32 AI agents working simultaneously to solve problems collaboratively |
| Performance | Scores 25.4% on Humanity’s Last Exam benchmark without tools; outperforms Google Gemini 2.5 Pro and OpenAI’s o3 | Scores 44.4% on the same benchmark with tools; significantly higher than competitors |
| Use Case | General AI tasks, accessible via $30/month subscription (SuperGrok) | Designed for enterprise and research use, part of $300/month SuperGrok Heavy subscription offering more powerful tools |
| Capabilities | Multimodal reasoning, real-time data access via X (formerly Twitter), advanced academic reasoning | Enhanced accuracy and fewer mistakes due to collaborative multi-agent approach, excels in complex tasks like scientific research and business analytics |
| Benchmark Highlights | PhD-level reasoning, strong in STEM fields | 87% on graduate-level physics test (GPQA), perfect 100% on AIME math exam, best-in-class scores overall |
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Grok 4 Heavy simulates a “study group” approach by having several AI agents “compare notes” to yield better answers, improving reasoning and reducing errors.
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Both models are part of Elon Musk’s vision to compete seriously with OpenAI’s ChatGPT, Google’s Gemini, and Anthropic’s Claude.
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Grok 4 integrates live information from social media platform X, keeping it updated with real-time events.
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Despite technical prowess, Grok models have faced controversies related to politically charged or offensive outputs in earlier versions, which the company claims to be addressing.
Grok 4 serves as a high-level, single-agent AI with broad capabilities, while Grok 4 Heavy is a premium, multi-agent system designed for more demanding, enterprise-level tasks with superior performance and accuracy