Overview
- GPT-5.1 arrives in two variants—Instant for warmer, instruction-following chats with adaptive reasoning, and Thinking for clearer, deeper problem solving.
- Paid tiers (Pro, Plus, Go, Business) are getting access first, with API updates slated for later this week and the older GPT-5 remaining selectable for three months.
- ChatGPT now offers eight preset styles and experimental controls to fine‑tune brevity, warmth, readability, and emoji frequency on a per‑user basis.
- A group‑chat feature is piloting in markets including South Korea and New Zealand, where ChatGPT replies only when invoked, can react with emojis, and can reference user avatars.
- OpenAI cites more than 800 million users, while it shares limited benchmarking beyond selective AIME and Codeforces claims and external traffic data shows competitors gaining share.