OpenAI · GPT-6 Model Family

GPT-6 Sol and Luna

Released 22 September, carrying GPT-6 Astra's strengths into faster, cheaper models. Sol is the balanced model for interactive and agentic coding needing multistep validation; Luna is the lightweight, lowest-cost model in the family for smaller, faster tasks. Sol drops to $2 and $10 per million input and output tokens from GPT-5.6 Sol's $4 and $20; Luna to $0.10 and $0.50 from $0.20 and $1.20. OpenAI states Sol makes about half as many mistakes as its predecessor on its own factuality evaluation, reaching Astra-level reliability at lower cost. Ships in ChatGPT Work, Codex and the API; Luna also in the desktop app and Free and Go tiers. openai.com returned 403, so this rests on secondary coverage.