OpenAI introduces GPT-6 Sol and Luna

9/24/2026

GPT-6 Sol and Luna bring lower-cost AI with stronger coding and efficiency Cut API costs by 50% and boost reuse in ChatGPT, Codex, and the API

OpenAI has introduced GPT6 Sol and GPT6 Luna, two new models designed to bring lowercost access to the company’s latest AI capabilities. The announcement says both models use similar training methods to GPT6 Astra, with a focus on efficiency, factuality, coding, computer use, and alignment. The company said API pricing for the new models is 50% lower than the GPT5.6 promotional prices. OpenAI also highlighted improvements in prompt caching and inference, saying these changes should help developers reuse context more efficiently and reduce operating costs for longerrunning applications. OpenAI said Sol and Luna are available today in ChatGPT Work and Codex for Plus, Pro, Business, Enterprise, and Edu users, with Luna also available to Free and Go users in the desktop app. In the API, the models are available as gpt6sol and gpt6luna.