Elon Musk's company xAI introduced the ultra-fast AI model Grok 4 Fast

Elon Musk's company xAI has announced the release of Grok 4 Fast – a new version of its flagship AI model, positioned as a faster and more economical alternative to Grok 4. This was reported by Engadget.

According to xAI, Grok 4 Fast demonstrates the same accuracy while using 40% fewer computational tokens. This key improvement reduces the cost of processing queries by approximately 98% compared to the original model, making it significantly more accessible for a wide range of tasks.

Grok 4 Fast is built on an innovative architecture that combines reasoning and non-reasoning modes. This approach, similar to strategies used by OpenAI (GPT-5) and Anthropic (Claude Opus), allows the model to automatically switch between deep analysis and rapid response generation. Thanks to this, Grok 4 Fast ranked first in the LMArena rating for search tasks and eighth in text response quality, showing results on real benchmarks that are comparable to or exceed its predecessor.

One of the main technical features of the new model is support for a context window of up to two million tokens, which significantly expands its capabilities for processing and analyzing large volumes of information. The model was trained using reinforcement learning methods and optimized for fast interaction with external tools, such as code execution or web search.

Grok 4 Fast is already available to end users through the OpenRouter and Vercel AI Gateway platforms, as well as via the xAI API for web applications, iOS, and Android. The cost of working with the model starts at $0.20 (approximately 17 rubles at the exchange rate as of September 21, 2025, – "Gazeta.Ru") per million tokens.