OpenAI launches GPT 6 Sol and Luna with Astra-level AI at lower cost, check details
Follow UsOpenAI has expanded its GPT 6 family with two new models, GPT 6 Sol and GPT 6 Luna.
The company has also cut API prices for both models by 50 per cent compared with the promotional pricing of GPT 5.6.
GPT 6 Sol and GPT 6 Luna are available in ChatGPT Work and Codex for Plus, Pro, Business, Enterprise and Edu users.
OpenAI has expanded its GPT 6 family with two new models, GPT 6 Sol and GPT 6 Luna. According to the company, the new models will help distribute the benefits of Astra’s intelligence by advancing the frontier on cost efficiency. Sol and Luna are designed to handle tasks such as professional work, coding, factual answers and computer use. The company has also cut API prices for both models by 50 per cent compared with the promotional pricing of GPT 5.6. Keep reading for the details.
SurveyOpenAI introduces GPT 6 Sol and GPT 6 Luna
GPT 6 Sol is designed for more demanding professional tasks. OpenAI says it can handle complex workflows while giving users more room to use the model because of its lower cost. On AutomationBench, GPT 6 Sol at its highest reasoning setting scored higher than Claude Opus 5 at its maximum setting, while costing only 9 per cent as much per task.
For coding, GPT 6 Sol also gets a major upgrade. On DeepSWE v1.1, it scored 68.8 per cent, compared with 69.9 per cent for Claude Fable 5 at its highest setting. OpenAI says Sol costs around 80 per cent less per task in this comparison.
Also read: OpenAI calls for global AI standards, warns about risks of recursive self-improvement
GPT-6 Sol and Luna just landed in Astra’s orbit.
— OpenAI Developers (@OpenAIDevs) September 22, 2026
Both launch today with API prices 50% lower than GPT-5.6.
Build with Sol. Scale with Luna. To production and beyond. pic.twitter.com/ZCEFp4JdjV
GPT 6 Luna is aimed at users who need strong performance at an even lower cost. OpenAI says Luna can match or exceed older models on several tests while using fewer resources.
The company has also improved the way both models communicate. OpenAI says users should see “more clarity, less jargon, fewer odd turns of phrase, fewer low-value details, and slightly shorter answers overall.”
OpenAI has also improved prompt caching. “We’ve improved prompt caching for GPT‑6 to deliver higher cache hit rates by default, helping agents reuse more context, respond faster, and benefit from discounts of 90 per cent on cached input-token reads,” it said.
Availability
GPT 6 Sol and GPT 6 Luna are available in ChatGPT Work and Codex for Plus, Pro, Business, Enterprise and Edu users. Free and Go users can access GPT 6 Luna through the desktop app. The models are not yet available in Chat. In the OpenAI API, they are available as gpt-6-sol and gpt-6-luna.
