OpenAI releases GPT-5.5 Instant as the new default model for ChatGPT

First recorded May 5, 2026 · Latest coverage May 5, 2026 · 1 source

OpenAI has released GPT-5.5 Instant and made it the new default model for ChatGPT, according to TechCrunch. The company says the model keeps the low latency of its predecessor while reducing hallucinations in sensitive domains including law, medicine, and finance.

Why it matters: A default-model upgrade in ChatGPT can quickly affect a very large user base, making even incremental changes to speed, reliability, and factual accuracy commercially and practically significant. Claimed reductions in hallucinations in high-stakes domains also matter for trust, safety, and how broadly users rely on general-purpose assistants for consequential tasks.

Sources

• OpenAI releases GPT-5.5 Instant, a new default model for ChatGPT TechCrunch · May 5, 2026