OpenAI Rolls Out GPT-5.1 With Smarter, More Conversational ChatGPT

OpenAI announced on its website the release of GPT‑5.1, an upgrade to its GPT‑5 series that enhances both intelligence and conversational quality in ChatGPT. The rollout begins with paid users and will expand to all users over the coming days.

GPT‑5.1 introduces two models: Instant and Thinking. GPT‑5.1 Instant, the default ChatGPT model, is described as more conversational and responsive while maintaining accuracy. GPT‑5.1 Thinking adapts its reasoning time based on question complexity, offering faster responses for simple queries and more detailed reasoning for complex ones. Both models are designed to more reliably follow user instructions and produce clearer, less technical answers.

The update also brings expanded customization options. ChatGPT users can now select from six tone presets—Default, Friendly, Efficient, Professional, Candid, and Quirky—and fine‑tune attributes such as warmth, conciseness, and emoji usage directly from personalization settings. These adjustments apply across all active chats and can be modified or reset at any time.

GPT‑5.1 Instant and Thinking are expected to reach the API later this week, under the names gpt‑5.1‑chat‑latest and GPT‑5.1, respectively. The previous GPT‑5 models will remain available for three months to allow users to compare performance before they are phased out. OpenAI said the update reflects continued improvements in capability, adaptability, and user control within the GPT‑5 generation.