We’re thrilled to present Grok 4 Fast, our latest advancement in cost-efficient reasoning models. Built on xAI’s learnings from Grok 4, Grok 4 Fast delivers frontier-level performance across Enterprise and Consumer domains—with exceptional token efficiency. This model pushes the boundaries for smaller and faster AI, making high-quality reasoning accessible to more users and developers. Grok 4 Fast features state-of-the-art (SOTA) cost-efficiency, cutting-edge web and X search capabilities, a 2M token context window, and a unified architecture that blends reasoning and non-reasoning modes in one model. (View Highlight)
We’re thrilled to present Grok 4 Fast, our latest advancement in cost-efficient reasoning models. Built on xAI’s learnings from Grok 4, Grok 4 Fast delivers frontier-level performance across Enterprise and Consumer domains—with exceptional token efficiency. This model pushes the boundaries for smaller and faster AI, making high-quality reasoning accessible to more users and developers. Grok 4 Fast features state-of-the-art (SOTA) cost-efficiency, cutting-edge web and X search capabilities, a 2M token context window, and a unified architecture that blends reasoning and non-reasoning modes in one model. (View Highlight)
We used large-scale reinforcement learning to maximize the intelligence density of Grok 4 Fast. In our evaluations, Grok 4 Fast achieves comparable performance to Grok 4 on benchmarks while using 40% fewer thinking tokens on average. (View Highlight)
We used large-scale reinforcement learning to maximize the intelligence density of Grok 4 Fast. In our evaluations, Grok 4 Fast achieves comparable performance to Grok 4 on benchmarks while using 40% fewer thinking tokens on average. (View Highlight)
This 40% increase in Grok 4 Fast’s token efficiency, combined with a significantly lower price per token, results in a 98% reduction in price to achieve the same performance on frontier benchmarks as Grok 4. As verified by an independent review from Artificial Analysis, Grok 4 Fast exhibits a state-of-the-art (SOTA) price-to-intelligence ratio compared to other publicly available models on the Artificial Analysis Intelligence Index. (View Highlight)
This 40% increase in Grok 4 Fast’s token efficiency, combined with a significantly lower price per token, results in a 98% reduction in price to achieve the same performance on frontier benchmarks as Grok 4. As verified by an independent review from Artificial Analysis, Grok 4 Fast exhibits a state-of-the-art (SOTA) price-to-intelligence ratio compared to other publicly available models on the Artificial Analysis Intelligence Index. (View Highlight)
Grok 4 Fast was trained end-to-end with tool-use reinforcement learning (RL). It excels at deciding when to invoke tools like code execution or web browsing. (View Highlight)
Grok 4 Fast was trained end-to-end with tool-use reinforcement learning (RL). It excels at deciding when to invoke tools like code execution or web browsing. (View Highlight)
Grok 4 Fast also establishes a new cost-effective frontier on general domain. We are excited to share Grok 4 Fast’s result on LMArena, where it has been privately battle-testing on the Search and Text Arenas. (View Highlight)
Grok 4 Fast also establishes a new cost-effective frontier on general domain. We are excited to share Grok 4 Fast’s result on LMArena, where it has been privately battle-testing on the Search and Text Arenas. (View Highlight)
