OpenAI o4-mini

OpenAI o4-mini was a generative pre-trained transformer model created by OpenAI. On April 24, 2025, the o4-mini model was released to all ChatGPT users (including free-tier users) as well as via the Chat Completions API and Responses API. Its retirement from ChatGPT was announced on January 29, 2026, and it was retired on February 13, 2026. Additionally, OpenAI introduced the o4-mini-high model, which was made available exclusively to paid-tier ChatGPT users. The high model was a slower model which had a higher reasoning effort to produce more accurate responses. Unlike earlier models, o4-mini was capable of processing both text and images. It also allowed to perform tasks like analyzing whiteboard sketches during its "chain-of-thought" phase.