GPT-5.5 Instant Is Not a Cosmetic ChatGPT Refresh but a Default Model Swap With Fewer Hallucinations and New Memory Controls
OpenAI has replaced ChatGPT’s default model with GPT-5.5 Instant, and the important change is not cleaner tone or fewer emojis. Starting May 5, 2026, the default experience for ChatGPT users shifted to a faster model that OpenAI says materially reduces hallucinations in medicine, law, and finance while adding a new way to see and manage…