GPT-6 Sol (US)

GPT-6 Sol is OpenAI's mid-tier model in the GPT-6 family, sitting below GPT-6 Astra and launched alongside GPT-6 Luna on September 22, 2026. According to OpenAI's announcement, Sol was trained with similar methods as Astra, carrying forward the frontier model's advances in professional work, factuality, coding, computer use, and alignment into a more accessible package. The launch positions Sol as part of a lineup designed to lead the cost–intelligence curve, distributing Astra-grade capabilities at lower price points through improvements in caching and inference infrastructure that OpenAI says it is passing directly to users.

In practical terms, GPT-6 Sol targets teams that want strong reasoning and coding performance for everyday production workloads without paying Astra-level rates. OpenAI frames the model as a balance between capability and efficiency, and third-party coverage of the launch highlights its roughly $2 per million input tokens and $10 per million output tokens pricing, about half the promotional rate of GPT-5.6 and aligned with comparable frontier-tier pricing. This combination of Astra-inherited strengths and lower operating cost makes Sol a fit for high-volume applications, agentic coding tasks, and customer-facing tools where alignment and reliability matter as much as raw price.