GPT Sol 6
Released on September 22, 2026
Changes from previous version
Successor to GPT Sol 5.6 at 50% of that generation's promotional $4/$20 rates. Brings Astra-class alignment, factuality, and communication style into the Sol tier, with higher cache hit rates by default and 90% discounts on cached input reads. Changing reasoning effort or tool availability no longer breaks the prompt cache.
Release Summary
GPT-6 generation of OpenAI's Sol tier for complex coding and agentic workflows, trained with similar methods as GPT Astra 6 at half the GPT Sol 5.6 promotional API price. Standard rates are $2/M input and $10/M output, with $0.20/M cache reads and $2.50/M cache writes. On AutomationBench, Sol at xhigh scores 33.2% at $0.27 per task, ahead of Claude Opus 5 at max (26.9%) at about 9% of that cost. Agents' Last Exam at max is 56.4%. DeepSWE v1.1 at max is 68.8%, within 1.1 points of Claude Fable 5 at xhigh. OSWorld 2.0 offline partial at xhigh is 60.5%. Available as gpt-6-sol in the API, ChatGPT Work, and Codex for Plus, Pro, Business, Enterprise, and Edu. 1.05M context, 128k max output, knowledge cutoff April 20, 2026. Fast mode is 2x Standard rates. Prompts over 272K input tokens are billed at 2x input and cache rates and 1.5x output.
Timeline
GPT-6 Sol released
OpenAI launches GPT-6 Sol as gpt-6-sol in the API, ChatGPT Work, and Codex, at $2/$10 per million tokens, alongside GPT-6 Luna. There is no GPT-6 Terra in this release.