ModelsFrontier model for complex professional workFrontier model for complex professional workGPT-5.6 Sol is the frontier model in the GPT-5.6 family. It roughly corresponds to the unsuffixed model tier used in earlier GPT-5 families. The gpt-5.6 alias routes requests to GPT-5.6 Sol. Reasoning.effort supports: none, low, medium (default), high, xhigh, and max.128,000 max output tokensFeb 16, 2026 knowledge cutoffPricingPricing is based on the number of tokens used, or other metrics based on the ...