OpenAI has launched a new family of LLMs called GPT-5.6, which comes in three distinct flavors: Sol, Terra, and Luna. Free users get almost nothing, as any access to GPT-5.6 models requires a subscription, though Free and Go users can access GPT-5.6 through ChatGPT Work. Plus or Business users can only get Sol at medium and higher effort settings, while Sol Pro is only available for Pro and Enterprise users. Per one million tokens, prices are $5 input and $30 output for Sol, $2.5 input and $15 output for Terra, and $1 input and $6 output for Luna. GPT-5.6 Sol is the smartest model, Terra is a balanced model for everyday work performing better than Anthropic's Fable 5 in some cases, and Luna is the cheapest, fastest, but least capable model for easy, non-crucial tasks like recipes and movie recommendations.