Improving GPT‑5.6 Sol in ChatGPT—and expanding access to GPT-5.6 Luna for free users

OpenAI is enhancing ChatGPT by improving GPT-5.6 Sol and expanding free user access to GPT-5.6 Luna. Internal evaluations showed GPT-5.6 Luna and GPT-5.6 Sol reduced factual errors by approximately 62% and 68% respectively, compared to GPT-5.5 Instant. These updates aim to make the latest models more widely available, improve answer reliability, and remove rate limits for free users, thereby increasing access and opportunity.