GPT-5 is OpenAI's flagship unified system, introduced on August 7, 2025, designed to route between fast general responses and deeper reasoning within a single model. Rather than being a single static checkpoint, it combines a smart efficient model for most questions with a deeper reasoning mode called GPT-5 thinking for harder problems, coordinated by a real-time router that decides which path to take based on conversation type, complexity, tool needs, and explicit user intent. This built-in thinking design is what OpenAI markets as putting expert-level intelligence into everyday interactions, removing the need for users to manually choose between separate models for quick versus careful answers.

OpenAI positions GPT-5 as state-of-the-art across coding, math, writing, health, and visual perception, presenting it as broadly capable rather than narrow. The visual perception angle hints at multimodal inputs beyond pure text, while the model's reach across professional domains such as science, finance, and law frames it as useful for both consumer and enterprise use. Distribution is layered: ChatGPT handles consumer and pro access, while separate developer and business surfaces expose the same underlying intelligence to API and workplace integrations, making it a practical fit for teams that want a single general-purpose model that can both answer quickly and reason carefully when tasks demand it.