The Archive

Learn how GPT-5.5 Instant improves ChatGPT’s health and wellness responses with stronger reasoning, better context, clearer communication, and physician-informed evaluations.

OpenAI begins rollout of GPT-5.5 Instant model variant in ChatGPT, positioning faster inference tier.

The new GPT-5.5 Instant model will replace GPT-3.5 Instant as the default model for ChatGPT

OpenAI's newest default model for ChatGPT might not make stuff up as much. Hallucinations have been an ongoing problem for AI models, but OpenAI says its new GPT-5.5 Instant model has "significant improvements in factuality across the board." The company claims that, based on "internal evaluations," GPT-5.5 Instant produced "52.5% fewer hallucinated claims" than its Instant model for GPT-5.3 "on high-stakes prompts covering areas like medicine, law, and finance." GPT-5.5 Instant also "reduced inaccurate claims by 37.3% on especially challenging conversations users had flagged for factual erro...

OpenAI releases GPT-5.5 Instant system card detailing model capabilities, limitations, and safety properties.

OpenAI releases GPT-5.5 Instant as ChatGPT's default model with improved accuracy, reduced hallucinations, and personalization controls.