GPT-5.5 Instant: ChatGPT's New Default Model in 2026
May 6, 2026
OpenAI's GPT-5.5 Instant replaces GPT-5.3 as ChatGPT's default model on May 5, 2026, cutting hallucinations 52.5% on medicine, law, and finance prompts.
OpenAI's GPT-5.5 Instant replaces GPT-5.3 as ChatGPT's default model on May 5, 2026, cutting hallucinations 52.5% on medicine, law, and finance prompts.