Overview
- Two variants debut: GPT-5.1 Instant aims for warmer, faster everyday replies with adaptive reasoning, while GPT-5.1 Thinking adjusts its thinking time for clearer outputs on complex tasks.
- Rollout prioritizes Pro, Plus, Go, and Business tiers, with free and logged‑out access to follow; legacy GPT‑5 models remain selectable for three months to ease the transition.
- OpenAI expands personalization with new tone presets such as Professional, Candid, and Quirky, plus experimental controls to tweak warmth, concision, and emoji use from settings.
- OpenAI reports internal benchmark gains for GPT-5.1 on AIME 2025 and Codeforces, and says API availability and enterprise/education previews are being staged this week.
- ChatGPT group chat enters pilot in Japan, New Zealand, South Korea, and Taiwan, running on GPT‑5.1 with options to have the bot reply when mentioned; previews indicate separate group custom instructions and no use of personal memory.