GPT-5.6 Luna outperforms GPT-5.5 on health reasoning, while being 25x cheaper

OpenAI's GPT-5.6 Luna outperforms GPT-5.5 on health reasoning while being 25x cheaper, marking a major advance in cost-effective AI intelligence.

GPT-5.6 is a major step forward for health intelligence. Across the lineup, we’re delivering stronger performance at lower cost: GPT-5.6 Luna outperforms GPT-5.5 at its highest reasoning setting while costing 25x less. Together, these advances raise quality while making advanced models accessible to more people globally.