OpenAI has launched GPT-5.1, an upgrade to its flagship model, available in two versions: GPT-5.1 Instant and GPT-5.1 Thinking.
The Instant model focuses on delivering warmer, more human-like conversations and stronger instruction-following, while the Thinking model is designed for efficiency fast on simple tasks and persistent on complex reasoning problems.
GPT-5.1 also introduces eight personality presets, including Professional, Friendly, Candid, Quirky, Efficient, Nerdy, and Cynical, giving users more control over tone and interaction style. The rollout begins immediately, with earlier GPT-5 models continuing in legacy mode for paid users.
