OpenAI launches GPT-5.1 with personality controls

OpenAI launched GPT-5.1 on November 12, 2025, improving ChatGPT with adaptive reasoning and a warmer tone. The update introduces GPT-5.1 Instant for light chat and Thinking for deeper analysis. Users can choose from six personalities and adjust warmth, brevity, and emoji use. Legacy GPT-5 models stay available for three months, emphasizing user customization and emotional engagement.