May 5, 2026•4 min read
OpenAI releases GPT-5.5 Instant, a new default model for ChatGPT
GPT‑5.5 Instant is a lighter, faster derivative of the full GPT‑5.5 architecture, optimized to deliver high‑quality answers with minimal delay. It replaces GPT‑5.3 Instant as the default model for ChatGPT, which means: