GPT-5 Thinking is the deeper reasoning mode within the GPT-5 unified AI system, designed to tackle complex, open-ended problems that require extended cognitive effort. It works alongside the faster GPT-5 model, dynamically engaging when queries demand more detailed analysis and thoughtful responses. This mode significantly reduces hallucinations and improves factual accuracy, producing more reliable answers on challenging topics like science, math, coding, and health. GPT-5 Thinking is also better at recognizing its own limitations, communicating clearly when tasks are impossible or underspecified. It incorporates advanced safety features to minimize harmful outputs and provide nuanced, helpful answers even in ambiguous or sensitive contexts. Available to all users, it helps bring expert-level intelligence to everyday and advanced use cases alike.