OpenAI Introduces GPT-5.6 Family: Three AI Models to Meet Diverse Needs

OpenAI has introduced its latest model family, GPT-5.6, which consists of three variants: Sol, Terra, and Luna. Each model is designed to cater to specific needs, with Sol targeting complex professional work and advanced reasoning, Terra aiming for a balance between capability and cost, and Luna suited for high-volume workloads where cost matters most.

The GPT-5.6 family has a 1.05 million token context window and a maximum output size of 128,000 tokens. Each model also supports several reasoning levels: none, low, medium, high, and max, giving teams control over the tradeoff between answer quality, speed, and cost without switching models.

OpenAI recommends testing on real project tasks rather than choosing a model based solely on size or complexity. The price gap across the GPT-5.6 family can significantly affect production budgets, with Sol costing $5 per 1 million input tokens and $30 per 1 million output tokens, Terra costing $2 per 1 million input tokens and $12 per 1 million output tokens, and Luna costing only $0.20 per 1 million input tokens and $1.20 per 1 million output tokens.

The strongest strategy for selecting an AI model is to start with the right GPT-5.6 model, set a sensible reasoning level, test real tasks, measure quality and cost, and then assess whether custom model behavior can add enough value. Fine-tuning should be used sparingly and only when supported models are needed for specific use cases.