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

OpenAI has rolled out an improved version of GPT-5.6 Sol in ChatGPT, focusing on enhanced accuracy and consistency across tasks. In parallel, free users gain expanded access to GPT-5.6 Luna, including unlimited everyday chats, a significant upgrade from prior limitations. This dual update reflects OpenAI's approach of offering a high-capability model (Sol) alongside a more accessible, lighter model (Luna) for routine interactions. The changes are likely to influence user engagement and subscription conversions, as free tier users experience the benefits of AI assistance more fully. No specific benchmarks or performance metrics were disclosed, but the update signals ongoing competitive pressure in the AI assistant space.