o4-mini (high) is a configuration of OpenAI's o4-mini reasoning model characterized by an increased reasoning effort setting. Released in April 2025, it belongs to the "o-series" of models designed to perform internal chain-of-thought processing before generating a response. This specific variant is optimized for users who require higher accuracy and consistency in complex tasks, such as advanced mathematics, scientific reasoning, and software engineering, by dedicating more computational time to the model's deliberation phase.
As a significant advancement over previous mini models in the series, the o4-mini architecture is multimodal by default. This allows the model to incorporate visual inputs—such as diagrams, charts, and whiteboard sketches—directly into its reasoning process. It also features enhanced agentic capabilities, enabling it to independently utilize integrated tools including Python code execution, web browsing, and image generation to resolve multi-step queries without manual intervention.
The model operates with a 200,000-token context window and can produce up to 100,000 output tokens. While its parameter count is proprietary and undisclosed, o4-mini (high) is positioned as a cost-efficient reasoning specialist. It offers performance levels approaching those of larger flagship models on benchmarks like SWE-bench and AIME, while maintaining the lower latency and reduced API costs typical of OpenAI's "mini" model tier.