OpenAI Makes GPT-5.5 Instant the Default ChatGPT Model — and Launches GPT-5.5-Cyber for Security Defenders
OpenAI had a big week. On May 5, 2026, the company made GPT-5.5 Instant the new default model powering ChatGPT — and then two days later launched a specialized security variant called GPT-5.5-Cyber for vetted defenders. Together, these moves push OpenAI’s competitive positioning significantly and add a new dimension to the AI model benchmark wars. GPT-5.5 Instant: The New Default GPT-5.5 Instant is now what ChatGPT users interact with by default. The headline metric: OpenAI claims it delivers 52.5% fewer hallucinations in high-stakes domains compared to its predecessor, making it notably more reliable for professional use cases. ...