Introducing GPT-6 Sol and Luna
OpenAI, Tuesday, September 22nd, 2026
OpenAI launched GPT-6 Sol and Luna, cheaper models built on GPT-6 Astra's methods, with API prices cut 50% from GPT-5.6 promotional rates.
OpenAI introduced GPT-6 Sol and GPT-6 Luna, trained with methods similar to GPT-6 Astra to bring its coding, factuality, computer-use and alignment advances to faster, more affordable tiers.
API prices for Sol and Luna are 50% lower than GPT-5.6's promotional pricing, made possible by caching and inference efficiency gains.
OpenAI says GPT-6 Sol at extra-high reasoning effort outperforms Claude Opus 5 at max effort on AutomationBench, a test of business workflows across apps, at just 9% of Opus 5's cost per task. Astra remains OpenAI's top overall model for the most demanding work.