OpenAI releases o3-mini
OpenAI o3-mini released — a cost-efficient small model in the reasoning series, with low, medium and high reasoning effort options
Why it matters
Previewed in December 2024, it launched the same day in ChatGPT Plus, Team and Pro and in the API for usage tiers 3–5, and free users could try it through the 'Reason' button — the first reasoning model offered to free ChatGPT users. OpenAI cited particular strength in science, math and coding
Source — Primary sources first; secondary reports are labelled “Press”
Officialopenai.comhttps://openai.com/index/openai-o3-mini/Added in Week 41, 2026 · See that week