GPT-5.6 Sol Improved, Free Users Get Luna
OpenAI is rolling out an improved GPT-5.6 Sol and a thinking-depth slider for ChatGPT Plus and Pro users, while switching the default model for free users to GPT-5.6 Luna and previewing unlimited text conversations. The company said internal evaluations showed a 68% drop in responses containing factual errors for GPT-5.6 Sol compared to GPT-5.5 Instant.























