Advancing the price-performance frontier with GPT-5.6

OpenAI announced price cuts and performance improvements for its GPT-5.6 model family on July 30, the company said. Starting that day, GPT-5.6 Luna will cost 80% less and GPT-5.6 Terra will cost 20% less. The lower prices are also reflected in usage counted against paid subscriptions for Codex and ChatGPT Work. OpenAI also introduced Fast mode in the API, replacing Priority Processing. For GPT-5.6 Sol, Fast mode delivers up to 2.5 times faster speeds than Standard processing at twice the price with no change in intelligence. Requests tagged priority will automatically use Fast mode. The company said the changes reflect years of improvements in how models are built, served, and put to work. OpenAI stated that making advanced intelligence more abundant and affordable is central to its mission to ensure artificial general intelligence benefits all of humanity. GPT-5.6 models take a more direct path through work, with better routing, optimized production software, and smarter context management reducing the time, tokens, and cost required for each result. Several partner companies provided testimonials. Replit President Michele Catasta said GPT-5.6 Luna is the closest the industry has come to intelligence too cheap to meter. Notion AI Product lead Hoda Noorian said Terra delivered comparable quality to GPT-5.5 at half the cost per task and in 60% less time. Ramp SWE-Bench creator Shaiyon Hariri said Terra and Luna lead on cost-efficiency across internal coding benchmarks.