OpenAI reduces prices for its GPT service
OpenAI has cut API prices for its GPT-5.6 Luna and Terra models and introduced a faster processing option for GPT-5.6 Sol. The changes also reduce how Luna and Terra usage is counted in ChatGPT Work and Codex.
The steepest cut applies to Luna, which now costs 80% less. Terra prices are down 20%. Sol pricing is unchanged, but the API now includes a Fast mode that offers quicker responses at a premium.
Terra costs USD $2 per million input tokens and USD $12 per million output tokens. Luna costs USD $0.20 per million input tokens and USD $1.20 per million output tokens.
Fast mode replaces OpenAI’s Priority Processing option for Sol. The service delivers up to 2.5 times faster speeds than standard processing at twice the price. Existing API requests tagged as priority will move automatically to the new mode.
The update affects several parts of OpenAI’s commercial product range. Terra and Luna remain available in ChatGPT Work, Codex, and the OpenAI API. Free and Go tier users in ChatGPT Work and Codex can access Terra, while paid users, including Plus, Pro, Business, and Enterprise, can choose both Terra and Luna.
OpenAI presented the changes as part of a broader effort to lower the cost of using large language models for routine business tasks. Lower prices make high-volume workloads such as document analysis, customer-interaction classification, and routine implementation more economical to run at scale, which is similar to how tech expectations are being re-evaluated in various industries.
One benchmark cited by OpenAI compared Luna with a rival model called Fable 5 on professional work measured by Agents’ Last Exam. According to the company, Luna outperformed that model at an estimated cost per task nearly 99% lower.
OpenAI’s pricing strategy reflects a broader trend in the AI market, where suppliers are offering corporate customers a menu of trade-offs between speed, quality, and price. They offer a range of models with different levels of complexity and cost.
OpenAI said Luna can use tools and complete multi-step workflows, expanding the range of jobs that can be handled at lower cost. It added that Luna delivers performance comparable to models that were at the frontier a year ago, at a fraction of the cost and at much higher speed.
The price cuts follow efficiency improvements in how OpenAI builds and runs its models. Gains came from model design, inference systems, and the software layer that links models with tools and context.
According to OpenAI, GPT-5.6 models now take a more direct route through work, with better routing of jobs across hardware, more efficient token generation, and context management that avoids repeating completed work. Those changes reduce the time, tokens, and cost required for each result.
For customers, the immediate effect is likely to be most visible in budgeting and workload allocation. Companies that had reserved larger models for a narrow set of tasks may now re-evaluate where lower-cost models can produce acceptable results, especially in coding, back-office workflows, and classification tasks, similar to how price cuts can impact business strategies.
OpenAI also said subscription prices and quota budgets for ChatGPT and Codex will not change, even though Terra and Luna usage will consume fewer credits. That means existing subscribers may be able to stretch current budgets further without moving to a higher plan.
They will maintain current pricing.
