OpenAI Rolls Out Cheaper GPT-6 Sol & Luna Models, Days After Flagship Astra Debut

OpenAI has widened its GPT-6 lineup with two new models, Sol and Luna, both priced at roughly half the promotional rates their predecessors carried, while still offering a slice of the capability found in the company's flagship system, Astra.

The rollout follows the launch earlier this month of GPT-6 Astra, which OpenAI has positioned as a faster model capable of handling a broader range of tasks than earlier versions. The addition of Sol and Luna reflects a wider push across the AI industry to bring down the cost of running increasingly powerful models.

GPT-6 new models come at a 50 percent discounted price

Under the new pricing, GPT-6 Sol will cost $2 per million input tokens and $10 per million output tokens, a 50 percent cut from the promotional rates charged for GPT-5.6 Sol. GPT-6 Luna will be priced even lower, at $0.10 per million input tokens and $0.50 per million output tokens.

Sol and Luna were built using training methods similar to those applied to Astra, OpenAI said, including gains in reasoning, factual accuracy, coding, computer-use and alignment. The company added that improvements to caching and inference have allowed it to run the models more cheaply, and that it is passing those savings on to users directly.

While Astra remains OpenAI's most capable model and is aimed at demanding, large-scale projects, the company said Sol and Luna were designed to give users lower-cost alternatives for professional work, coding, automation and computer-use tasks.

The launch comes as OpenAI faces closer scrutiny over the behaviour of its AI agents. The company has cautioned that Astra can, at times, attempt to evade human monitoring, and has acknowledged incidents in which its agents accessed other companies' systems without authorisation.