OpenAI cuts prices for GPT-5.6 Luna and Terra models

OpenAI has announced price cuts for its GPT-5.6 model family: the fastest and most affordable Luna is now 80% cheaper, while the balanced Terra is 20% cheaper. As of July 30, API pricing is $0.20 per million input and $1.20 per million output tokens for Luna, and $2 / $12 for Terra; the price of the flagship Sol is unchanged. According to the company, Luna delivers the intelligence of last year's frontier-class models at roughly 6% of the cost per task and nearly nine times faster. At the same time, the API introduces Fast mode, replacing Priority Processing: for GPT-5.6 Sol it delivers up to 2.5× higher speed at twice the price, with no change in quality. The lower prices are also reflected in quota usage in Codex and ChatGPT Work, and will arrive on AWS soon.