GPT o4-mini-high
o4-mini-high is the higher reasoning-effort setting of OpenAI's o4-mini model, offered in the ChatGPT model picker from April 2025 until o4-mini was retired from ChatGPT in February 2026. It spends more inference-time compute per answer than the default o4-mini setting, which raises accuracy on harder reasoning tasks at the cost of latency. It is the same underlying o4-mini model run with a higher reasoning-effort setting, not a separately trained model with a different architecture. In the API the same behavior is reached by raising the reasoning effort parameter on o4-mini rather than by selecting a different model name. The trade-off is straightforward: longer chains of thought give better results on multi-step mathematics, coding and analysis, at the cost of slower and more expensive answers than the default setting.
It is chosen for business analysis, research assistance, technical problem-solving and decision support, where an answer is worth waiting longer for; routine queries stay on the default setting. Because it is a setting rather than a separate model, it is not offered as its own API model name; integrations select o4-mini and raise its reasoning effort.
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