xAI: Grok 4 Fast

Grok 4 Fast, xAI's latest multimodal model, demonstrates a balanced performance profile with notable strengths in reliability and specific accuracy benchmarks. With a 2M token context window and available in both non-reasoning and reasoning flavors, it was created on September 18, 2025. The model exhibits moderate speed performance, ranking in the 21st percentile across two benchmarks, and offers moderate pricing, placing it in the 39th percentile. A standout feature is its exceptional reliability, achieving a 100% success rate across all benchmarks, indicating consistent and usable responses. In terms of specific performance, Grok 4 Fast achieved 94.0% accuracy in the Coding (Baseline) benchmark, placing it in the 93rd percentile, though with a relatively high duration. Its performance in the Ethics (Baseline) benchmark was particularly impressive, achieving perfect 100.0% accuracy. This makes it the most accurate model at its price point and among models of comparable speed for ethical reasoning. While its speed is moderate, its high accuracy in critical areas like ethics and strong coding performance, coupled with its perfect reliability, position Grok 4 Fast as a robust and dependable option, especially for applications requiring high accuracy and consistent output.