GPT-5.4 is designed as a single frontier system that merges OpenAI's recent reasoning, coding, and agentic advances into one model, explicitly incorporating the coding capabilities of GPT-5.3-Codex while improving how it handles tools, software environments, and professional work involving spreadsheets, presentations, and documents. The intended use is broad but professional: producing production-quality code, synthesizing information across multiple sources, and executing complex multi-step workflows with fewer iterations and better token efficiency. In ChatGPT the model ships as GPT-5.4 Thinking, which can surface an upfront plan of its reasoning so users can steer it mid-response, and a GPT-5.4 Pro tier is offered alongside for maximum performance on hard tasks.

Qualitatively, GPT-5.4 is positioned as a strong default for both general-purpose work and software engineering, with deep web research and long-context reasoning tuned for highly specific queries. Its context behavior is a defining practical strength, handling roughly a million tokens across a large input window plus a sizable output window so that high-context reasoning, coding, and multimodal analysis can happen inside the same workflow. It is also the first general-purpose OpenAI release with native state-of-the-art computer-use capabilities in Codex and the API, enabling agents to operate computers and carry out complex cross-application workflows, which makes it a particularly good fit for teams building agentic coding assistants and long-horizon research or document pipelines.