Introduction

"Today we’re upgrading the GPT‑5 series with the release of: GPT‑5.1 Instant: our most-used model, now warmer, more intelligent, and better at following your instructions. GPT‑5.1 Thinking: our advanced reasoning model, now easier to understand and faster on simple tasks, more persistent on complex ones. We heard clearly from users that great AI should not only be smart, but also enjoyable to talk to. GPT‑5.1 improves meaningfully on both intelligence and communication style. We’re also making it easier for you to shape ChatGPT’s tone. Preferences on chat style vary—from person to person and even from conversation to conversation—so we’re introducing more intuitive and effective controls so ChatGPT can better match the tone you want in responses."

Benchmarking