OpenAI cuts GPT-6 Sol and Luna prices 50%, lowering costs behind business software AI
OpenAI says its two new models cost half as much to run, which sets the cost of the AI features inside software small businesses already pay for.
By 
Midwatch Radar Updated
Produced with AI assistance and checked against primary sources. Our standards
OpenAI introduced GPT-6 Sol and GPT-6 Luna, two new AI models, on September 22, 2026, according to trade coverage [2][3]. OpenAI’s announcement page shows no publication date, only an update note dated September 29, 2026 [1]. OpenAI says it reduced API prices for both models by 50% compared with their GPT-5.6 promotional pricing [1]. The API is how software makers buy access to the models, billed per token, a token being a small chunk of text about the size of a word fragment.
Per million input tokens, Sol dropped from $4 to $2 and Luna from $0.20 to $0.10, according to OpenAI [1]. Output prices fell from $20 to $10 for Sol and from $1.20 to $0.50 for Luna [1].
OpenAI also says Sol makes about half as many mistakes as its predecessor, and that at high effort Luna improves on its predecessor by 5.4 percentage points at 58% lower cost per task on AutomationBench, a test of business tasks across apps [1]. These results come from OpenAI and have not been independently verified by Midwatch Radar. The models are available in ChatGPT Work and Codex on paid plans [3].
Many business tools that small companies already pay for now include AI features, such as drafting replies, summarizing calls, tagging records or answering the phone. The software maker typically pays an AI provider by usage for each of those actions, so a lower per-token price lowers that cost.
Whether the saving reaches a subscriber depends on how each software company prices its own plans, and the sources do not cover that. The price cut applies to vendors that use OpenAI models, and other AI providers set their own prices. OpenAI measures the 50% cut against GPT-5.6 promotional pricing, so the comparison point matters when reading the figure [1]. The accuracy gains are OpenAI’s own claims.
- Whether software vendors that build on OpenAI models announce price or plan changes. The sources list none.
- Independent testing of OpenAI’s accuracy and cost claims. As of October 2, OpenAI’s page is the source for those figures [1].
- OpenAI’s page carries a September 29, 2026 update pointing to a newer model, GPT-6.1 Sol, so details on it may change [1].