What’s New In ChatGPT 5.1? Hidden Features And Human-Like Conversation Capabilities Revealed

OpenAI has officially unveiled GPT-5.1, the latest evolution of its flagship AI model, featuring two advanced variants—GPT-5.1 Instant and GPT-5.1 Thinking. This major update focuses on delivering more natural, engaging conversations while dramatically improving reasoning and task performance. The release comes just three months after the debut of GPT-5, which drew criticism from users for feeling “cold” and inconsistent compared to previous versions.GPT-5.1 Instant now powers most ChatGPT conversations, offering faster, more lifelike dialogue, while GPT-5.1 Thinking handles deeper and more complex reasoning tasks. Both models can dynamically assess question difficulty, spending extra processing time on challenging problems and giving quicker responses to simpler ones—making conversations smoother and more efficient.GPT-5.1 Introduces Eight Personalities and Customizable Tone ControlsOne of GPT-5.1’s most exciting updates is its new personality presets. Users can now choose from eight distinct modes—Default, Professional, Friendly, Candid, Quirky, Efficient, Nerdy, and Cynical—to shape the AI’s tone and conversational style. Additional customization tools let users adjust warmth, brevity, and even emoji usage in real time, ensuring a more personal chat experience. The feature applies instantly across all chats, both existing and new.Paid users under Pro, Plus, Go, and Business plans will be the first to access GPT-5.1, while free-tier users will receive the update soon after. Enterprise and Education plan subscribers will enjoy a one-week preview window before GPT-5.1 becomes the default model.Stronger Performance, Clearer Explanations, and Broader RolloutOpenAI notes that GPT-5.1 delivers major improvements in mathematical reasoning and coding, outperforming GPT-5 in benchmarks like AIME 2025 and Codeforces. The Thinking variant also simplifies complex topics, removing unnecessary jargon and explaining intricate ideas in clear, accessible language.The update reflects OpenAI’s effort to make AI feel “not only smart but also enjoyable to talk to,” according to Fidji Simo, CEO of Applications at OpenAI. GPT-5.1 aims to balance intellectual depth with emotional warmth—a combination that many users felt was missing in GPT-5.Both GPT-5.1 Instant and GPT-5.1 Thinking will be available via the API later this week, with a gradual rollout planned to ensure platform stability. Legacy GPT-5 models will remain available for the next three months in a dropdown menu for paying users, giving everyone time to adjust to OpenAI’s smarter, friendlier new AI companion.