GPT-5.5 Instant: ChatGPT's New Default Model Explained

OpenAI just released a major upgrade to ChatGPT, making GPT-5.5 Instant the new default model for everyone. This new version drastically cuts down on factual errors, by over 52% compared to previous models. Here's the thing: it's much better at high-stakes tasks in medicine, law, and finance. The model can now spot and correct its own mistakes in complex problems, like algebra. What's interesting is that it's also more efficient, using 30% fewer words while staying just as informative. ChatGPT now has "Smart Routing," which automatically uses a more powerful model for tough questions without extra cost. Plus, a new "Memory Sources" feature lets you see and even delete past conversations that influenced a response, giving you more control over your privacy. This upgrade means a more accurate, efficient, and personalized experience for every user.