Improving GPT‑5.6 Sol in ChatGPT—and expanding access to GPT-5.6 Luna for free users Improving GPT‑5.6 Sol in ChatGPT—and expanding access to GPT-5.6 Luna for free users openai.com/ai 2026-08-06 1 min read original #product ChatGPT introduces improved GPT-5.6 Sol with better accuracy and consistency, plus expanded access for free users and unlimited everyday chats with GPT-5.6 Luna.