OpenAI says the accuracy improvements are most notable in high stakes subject areas. In internal testing, GPT 5.5 Instant produced 52.5% fewer hallucinated claims than its predecessor on prompts covering medicine, law, and finance, and 37.3% fewer inaccurate claims on conversations users had previously flagged for errors. GPT 5.5 Instant is starting to roll out in ChatGPT. It’s a big upgrade, giving you smarter, clearer, and more personalized answers in a warmer, more natural tone. And...
