OpenAI expands GPT-6 lineup with Sol and Luna models, bringing cheaper, more efficient AI
OpenAI is widening access to its latest AI capabilities with two lower-cost models, targeting professionals, developers and businesses that need stronger performance without higher computing costs.
- Sep 23, 2026,
- Updated Sep 23, 2026 2:44 PM IST
OpenAI has expanded its GPT-6 model family with two new AI models aimed at making advanced AI more affordable for everyday work and high-volume use. The company has introduced GPT-6 Sol and GPT-6 Luna, positioning them below GPT-6 Astra while bringing several of the capabilities behind Astra to lower-cost models. The new models are designed for professional work, coding, computer use and other demanding tasks, with OpenAI also highlighting improvements in efficiency.
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The company says better caching and inference have helped reduce serving costs, allowing it to cut API prices for both models by 50% compared with GPT-5.6 promotional pricing. GPT-6 Astra, however, remains OpenAI's flagship model for its highest level of performance.
GPT-6 Sol and Luna: What’s new
GPT-6 Sol is designed for more demanding professional work, coding and agentic workflows, while Luna focuses on efficient, repeatable and high-volume tasks. OpenAI says Sol can handle complex tasks while offering higher usage limits at a lower cost. In AutomationBench, GPT-6 Sol at high effort outperformed Claude Opus 5 at maximum effort at 9% of its cost per task. Luna also improved on GPT-5.6 Luna by 5.4 percentage points at high effort while costing 58% less per task.
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For coding, OpenAI says Sol substantially improves on GPT-5.6 Sol on FrontierCode and can match Claude Fable 5.1 xhigh at a much lower cost. For computer use, Sol at xhigh scored 60.5% on OSWorld 2.0 offline, compared with 60.3% for Claude Opus 5 at medium effort, while costing about 80% less per task.
GPT-6 API pricing gets cheaper
GPT-6 Sol costs $2 per 1 million input tokens and $10 per 1 million output tokens. Luna costs $0.10 for input and $0.50 for output per 1 million tokens. OpenAI says both models are 50% cheaper than their respective GPT-5.6 promotional prices.
The models are available through the OpenAI API, while GPT-6 Sol and Luna are also available in ChatGPT Work and Codex for Plus, Pro, Business, Enterprise, and Edu users. If you are a Free or Go user, then you can access GPT-6 Luna in the desktop app.
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OpenAI has expanded its GPT-6 model family with two new AI models aimed at making advanced AI more affordable for everyday work and high-volume use. The company has introduced GPT-6 Sol and GPT-6 Luna, positioning them below GPT-6 Astra while bringing several of the capabilities behind Astra to lower-cost models. The new models are designed for professional work, coding, computer use and other demanding tasks, with OpenAI also highlighting improvements in efficiency.
Must Read: Nvidia CEO Jensen Huang says there is a “0% chance AI will end the world by 2030”
The company says better caching and inference have helped reduce serving costs, allowing it to cut API prices for both models by 50% compared with GPT-5.6 promotional pricing. GPT-6 Astra, however, remains OpenAI's flagship model for its highest level of performance.
GPT-6 Sol and Luna: What’s new
GPT-6 Sol is designed for more demanding professional work, coding and agentic workflows, while Luna focuses on efficient, repeatable and high-volume tasks. OpenAI says Sol can handle complex tasks while offering higher usage limits at a lower cost. In AutomationBench, GPT-6 Sol at high effort outperformed Claude Opus 5 at maximum effort at 9% of its cost per task. Luna also improved on GPT-5.6 Luna by 5.4 percentage points at high effort while costing 58% less per task.
Must Read: OpenAI to retire GPT-5.5 from ChatGPT, Work and Codex on October 14: What changes to expect
For coding, OpenAI says Sol substantially improves on GPT-5.6 Sol on FrontierCode and can match Claude Fable 5.1 xhigh at a much lower cost. For computer use, Sol at xhigh scored 60.5% on OSWorld 2.0 offline, compared with 60.3% for Claude Opus 5 at medium effort, while costing about 80% less per task.
GPT-6 API pricing gets cheaper
GPT-6 Sol costs $2 per 1 million input tokens and $10 per 1 million output tokens. Luna costs $0.10 for input and $0.50 for output per 1 million tokens. OpenAI says both models are 50% cheaper than their respective GPT-5.6 promotional prices.
The models are available through the OpenAI API, while GPT-6 Sol and Luna are also available in ChatGPT Work and Codex for Plus, Pro, Business, Enterprise, and Edu users. If you are a Free or Go user, then you can access GPT-6 Luna in the desktop app.
For Unparalleled coverage of India's Businesses and Economy – Subscribe to Business Today Magazine