OpenAI: GPT-5.6 Luna Default for Free & Go ChatGPT Users

OpenAI is making GPT-5.6 Luna the default model for free and Go ChatGPT users. This change is expected to begin this week. Here's the thing: Free and Go users will also get unlimited text chats starting next week. This update replaces GPT-5.5 Instant with GPT-5.6 Luna, which is the smallest of OpenAI's three GPT-5.6 models. What's interesting is that OpenAI is also introducing a new "Think" button. This feature gives users more control over how much reasoning ChatGPT uses in its responses. The "Think" button will also be available to Plus and Pro subscribers. For paid users, GPT-5.6 Sol is getting an update. This updated model aims to provide more direct answers and reduce factual errors. The bottom line: These changes will affect how many users interact with ChatGPT's features and capabilities.