Overview
- GPT‑5.1 ships in Instant for fast, instruction‑tight replies and Thinking for advanced reasoning, with an Auto mode choosing between them per request.
- Distribution starts for Pro, Plus, Go and Business users, with Enterprise and Education receiving early access and free users slated to follow within days.
- Expanded personalities and finer tone controls let users select styles such as Friendly, Efficient, Professional, Cynical, Nerdy and Quirky, and the assistant can suggest tone adjustments.
- OpenAI says instruction following, logical reasoning and clarity are improved compared with GPT‑5, and GPT‑5 Pro is being updated to GPT‑5.1 Pro.
- API endpoints are slated to arrive this week as gpt‑5.1‑chat‑latest (Instant) and GPT‑5.1 (Thinking), and a System Card addendum details safety upgrades.