GPT-6 Sol and Luna are now available to provide a faster and more affordable pathway to the intelligence found in the Astra model. These updates include a 50% cut in API pricing compared to GPT-5.6 promotional rates, with Sol priced at $2 per million input tokens and $10 per million output tokens. Luna costs $0.10 per million input and $0.50 per million output. The models are rolling out in ChatGPT Work and Codex for Plus, Pro, Business, Enterprise, and Edu users, while Free and Go users can access Luna via the desktop app.

The releases target a higher cost efficiency frontier but show varied results in external benchmarking. Artificial Analysis reports that GPT-6 Sol cut its hallucination rate from 92% to 60%, though the model declines to answer questions more often than its predecessor. While Sol's Coding Agent Index score rose to 57, Luna's score dropped 2 points to 41. Both models also exhibited regressions in knowledge work evaluations, specifically within the GDPval-AA v2.1 and AA-Briefcase v1.1 benchmarks.