OpenAI now uses GPT-5.6 Sol for both Instant and Thinking across ChatGPT Plus and Pro.
Free and Go users will receive GPT-5.6 Luna as the default model, unlimited text chats, and a Think button for harder questions.
Previously, moving from Instant to higher reasoning effort could feel like switching models because the tone and behavior changed with it.
The new slider adjusts how much thought ChatGPT puts into a response while keeping GPT-5.6 Sol underneath.
Says its internal finance, medicine, and law evaluation found factual errors were 68% less common than with GPT-5.5 Instant.
We're making better intelligence easier to access in ChatGPT for everyone: - GPT-5.6 Sol now powers both Instant and deep reasoning for Plus & Pro users, delive...