xAI Introduces Cost-Effective Grok 4 Fast

Elon Musk's xAI has unveiled Grok 4 Fast, a new AI model designed to handle both reasoning and non-reasoning tasks simultaneously. The model is more efficient, using 40% fewer tokens than its predecessor while maintaining the same level of accuracy. Users can access it via xAI's website, mobile apps, OpenRouter, and Vercel AI Gateway, with free access available on some platforms during the launch period.

Grok 4 Fast is capable of processing extensive documents due to its large 2 million token context window. It has achieved high scores on major benchmarks this year, including 85.7% on GPQA Diamond, 92% on AIME 2025, and 93.3% on HMMT 2025, matching the performance of its predecessor.

Notably, the cost is just $0.20 per million input tokens, with pricing scaling based on token usage. For large projects or those requiring fast, affordable AI without compromising accuracy, Grok 4 Fast could be a game changer, offering up to a reported 98% cost reduction compared to Grok 4.