OpenAI: GPT-5.1 Chat

GPT-5.1 Chat, released by OpenAI on November 13, 2025, is positioned as a fast, lightweight model optimized for low-latency chat. It performs among the fastest models, typically ranking in the top tier for speed (66th percentile across 8 benchmarks). The model offers moderate pricing, placing in the 23rd percentile. Notably, GPT-5.1 Chat demonstrates exceptional reliability, achieving a 100% success rate across all 8 benchmarks, indicating minimal technical failures. The model exhibits outstanding performance in several key areas. It achieved perfect accuracy in Hallucinations, General Knowledge, and Ethics benchmarks, often being the most accurate model at its price point and speed. Its adaptive reasoning capabilities are evident in strong scores for Instruction Following (93rd percentile), Reasoning (84th percentile), and Coding (91st percentile), suggesting proficiency in complex tasks. While its Mathematics accuracy at 93.0% is solid (77th percentile), it's not as universally perfect as its knowledge-based scores. Email Classification shows competent performance at 98.0% accuracy (58th percentile). Overall, GPT-5.1 Chat's strengths lie in its remarkable accuracy across foundational knowledge and ethical reasoning, coupled with robust instruction following and coding abilities, all delivered with high speed and reliability. Its primary weakness, if any, is a slightly less dominant performance in the most challenging mathematical problems compared to its perfect scores elsewhere.