OpenAI Releases GPT-6 Sol and GPT-6 Luna
2026-09-22 ยท Frontier Models
OpenAI released two lower-cost models in its GPT-6 family, positioned below the flagship GPT-6 Astra.
OpenAI released GPT-6 Sol and GPT-6 Luna on September 22 in its API, ChatGPT Work, and Codex, at about half the price of their GPT-5.6 predecessors. Sol is the high-end, cost-efficient tier for professional work, agentic coding, and computer use; Luna is the fast, low-cost tier for high-volume tasks. OpenAI says Sol makes about half as many mistakes as its predecessor on internal factuality evaluations.
The release matters to SIRDA because capabilities first shown in a frontier system move quickly into cheaper, more widely deployed models. Governance and evaluation have to follow how fast advanced capabilities spread, as well as the most capable model at any moment.
Performance figures are OpenAI's own. Its safety documentation is the company's assessment, not an independent certification.