OpenAI: GPT-5.6 Terra

OpenAI's GPT-5.6 Terra, created on July 9, 2026, is positioned as a balanced model within the GPT-5.6 series, excelling in everyday coding, reasoning, and agentic tasks. It consistently ranks among the fastest models, performing in the 88th percentile across eight benchmarks. Its pricing is moderate, falling within the 28th percentile. A standout feature is its exceptional reliability, demonstrating a 100% success rate across all benchmarks, indicating minimal technical failures. In terms of performance, GPT-5.6 Terra exhibits perfect accuracy in General Knowledge, making it the most accurate model at its price point and among models of comparable speed. It also shows strong performance in Coding (95.0% accuracy, 90th percentile) and Reasoning (98.0% accuracy, 89th percentile), both achieving the "most accurate among models this fast" distinction. Instruction Following is also a strength at 81.0% accuracy (86th percentile). While its Hallucinations (96.0% accuracy) and Email Classification (98.0% accuracy) are solid, they fall closer to the median percentile. Ethics (99.0% accuracy) and Mathematics (94.0% accuracy) also demonstrate robust capabilities. The model's primary weakness appears to be its relatively high duration in several benchmarks, particularly General Knowledge, Ethics, and Coding, despite its overall high speed ranking.