GPT-6.1 Sol is OpenAI's September 29th, 2026 Sol refresh — near-Astra everyday help at Sol's $2/$10 price. Our tests score helpfulness 99.0, instruction following 98.5, and comprehension 99.5, just behind GPT-6 Astra. Empathy is 93.5: direct and short, not chatty. Creative writing is 87.5: on-brief workplace prose, not literary. Speed is 73.0, a bit snappier than Astra. Best when you want Astra-like follow-through without Astra's bill.