GPT-5.6 tiers give IT teams a model-routing strategy

GPT-5.6 arrived as a three-tier family. Sol targets the hardest reasoning and long-running agent tasks, Terra is the balanced default for everyday interactive and agentic work, and Luna targets faster, lower-cost tasks.

For IT teams, the important decision is routing rather than choosing a single universal model: reserve Sol for high-value exceptions, use Terra for core work and set Luna as the economical default for high-volume tasks.