xAI Launches Grok 4 Fast: A More Efficient and Cost-Effective AI Model

xAI debuts a faster and more cost-effective version of Grok 4

A few months after the release of Grok 4 and an extremely problematic antisemitic meltdown of its chatbot, xAI is already trying to move on with its latest AI model. Elon Musk's xAI announced the release of Grok 4 Fast, a faster, more efficient reasoning model compared to its recent predecessor. According to xAI, Grok 4 Fast offers similar performance to Grok 4 while using 40 percent fewer thinking tokens on average. Along with faster results, xAI said Grok 4 Fast "results in a 98% reduction in price to achieve the same performance on frontier benchmarks as Grok 4," whether it's handling tasks that involve writing code or just browsing the web for quick responses. Similar to OpenAI's GPT-5 that alternates between a smart, efficient model and a deeper reasoning model, xAI's latest update includes a unified architecture that can transition between handling complex requests with its "reasoning" model and quick responses through its "non-reasoning model." In tests on LMArena, a platform that pits AI models against each other and provides side-by-side comparisons, Grok 4 Fast ranks first in search-related tasks and eighth in text-related tasks. xAI made Grok 4 Fast available for all users, including the free ones, on web, iOS and Android. However, with how competitive the LLM race is getting, it's only a matter of time before Google releases the next-gen version of Gemini or Anthropic updates the Claude Opus model beyond the recently released 4.1 version.

Elon Musk's xAI Launches Grok 4 Fast With 2M Token Limit and 40% Lower Costs

xAI Launches Grok 4 Fast, Cutting Token Use by 40% While Matching Grok 4 Accuracy. Available Across Web, Apps, and APIs with Flexible Pricing Elon Musk's xAI has launched a new AI model, Grok 4 Fast. The model aims to keep costs low and maintain competitive accuracy by combining non-reasoning and reasoning abilities into a single system, thereby eliminating the need for separate frameworks. According to , Grok 4 Fast uses approximately 40% of the number of thinking tokens used by Grok 4. The performance levels are benchmarked with fewer tokens, yet the results are close to Grok 4. Based on the objective exploration done by Artificial Analysis, Grok 4 Fast could run with 98% less money while maintaining the same performance to improve its cost-performance ratio. The in AIME 2025, HMMT 2025, and the GPQA Diamond test gave scores of 85.7%, 92%, and 93.3%, respectively. Additionally, the model scored 95% on SimpleQA and 74% on X Bench Deepsearch, meaning that it can be applied to various tasks, including code execution and sophisticated search.