Overview
- OpenAI began rolling the upgrade out Tuesday to all ChatGPT users, listing the API version as chat-latest and keeping GPT-5.3 Instant for paid users during a three-month transition.
- The company says internal tests show 52.5% fewer hallucinated claims on high-stakes prompts and a 37.3% drop in inaccurate claims on tough, user-flagged chats.
- A new memory sources view shows which past chats, files, or connected Gmail shaped a reply, and users can view, delete, or correct those items.
- Enhanced personalization that pulls context from past activity is reaching Plus and Pro on the web first, with mobile and other tiers coming in the weeks ahead.
- OpenAI’s system card labels the model high capability in cybersecurity and biological areas, which triggers extra automated safeguards, and outside testing is still pending.