On August 7, 2026, OpenAI announced that it would upgrade the default model to GPT-5.6 LUNA for free users and expand usage permissions to provide unlimited text chat services. For Plus and Pro users, OpenAI is updating GPT-5.6 SOL in chats to make it more reliable in factual accuracy and provide more focused answers. Plus and Pro users can now use the updated GPT-5.6 SOL version and the new slider feature in ChatGPT starting today.