GPT-6 Sol

GPT-6 Sol launched on September 22, 2026 alongside GPT-6 Luna as cheaper offshoots of the flagship GPT-6 Astra, built with similar training methods for gains in professional work, factuality, coding, computer use, and alignment. OpenAI positions Sol as the everyday-work tier: it makes roughly half as many mistakes as its predecessor GPT-5.6 Sol on the company's internal factuality evaluations, and reaches near-Astra reliability on agentic benchmarks.

Pricing is $2 per million input tokens and $10 per million output, half the GPT-5.6 Sol rates, with improved prompt caching aimed at agents that reuse context. It carries a 1.05M-token context window. On October 7, 2026 Sol began rolling out as the ChatGPT Chat model for Plus, Pro, Business, and Enterprise users, paired with the new Intelligent UI that renders answers as interactive charts, forms, and tools. The honest caveats: published scores are OpenAI's own and unreplicated independently, and a week after launch GPT-6.1 Sol superseded it as the recommended API/Work/Codex model.