Introducing GPT-6 Sol and Luna
OpenAI is adding two cheaper GPT-6 models, Sol and Luna, with API prices cut 50% from GPT-5.6 promotional levels.
Sol and Luna are positioned below GPT-6 Astra, which OpenAI still calls its strongest model. The company says both models bring Astra-derived gains in professional work, factuality, coding, computer use, and alignment to faster, lower-cost tiers. OpenAI also says prompt caching has improved for GPT-6, with cached input reads discounted by 90%. The models are available in ChatGPT Work, Codex, and the API, with broader ChatGPT rollout planned gradually. OpenAI's note
Sol and Luna are positioned below GPT-6 Astra, which OpenAI still calls its strongest model. The company says both models bring Astra-derived gains in professional work, factuality, coding, computer use, and alignment to faster, lower-cost tiers. OpenAI also says prompt caching has improved for GPT-6, with cached input reads discounted by 90%. The models are available in ChatGPT Work, Codex, and the API, with broader ChatGPT rollout planned gradually. OpenAI's note
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