OpenAI has launched o3-mini, a new reasoning model, which is now available to both free and paid ChatGPT users. This follows Microsoft making its O1 model free for all Copilot users and the rise of DeepSeek, which has shaken up the AI industry.

With o3-mini, OpenAI is giving free-tier users access to its reasoning models for the first time, although there will be rate limits similar to GPT-4o. This is a significant shift in OpenAI’s approach, as it makes advanced AI tools available to a larger audience. The model, which was first revealed at OpenAI's "12 Days of Ship-mas" event in December, performs similarly to o1-mini, its predecessor, in domains like science reasoning, coding and mathematics. On the other hand, it improves step-by-step reasoning skills and response speed by 24%, essentially providing total accuracy and usability of its results.

"This powerful and fast model advances the boundaries of what small models can achieve, delivering exceptional STEM capabilities—with particular strength in science, math and coding—all while maintaining the low cost and reduced latency of OpenAI o1-mini," the company said in its blog post. Additional features will be available to paid users on ChatGPT Plus, Team and Pro plans. Plus and Team users can now send up to 150 messages per day, which is three times the previous restriction. Pro users, who pay $200 a month, will still have unlimited access. Through OpenAI's API offerings, such as the Assistants API, Batch API, and Chat Completions API, developers can incorporate o3-mini. O3-mini-high, an enhanced version of OpenAI designed for coding and complicated reasoning tasks, has also been released. It provides more intelligence at the expense of marginally longer processing times. 

A major improvement in o3-mini is its ability to fetch live data from the web, giving users answers with source links for better reliability. It is also being integrated into Microsoft’s Azure OpenAI Service, GitHub Copilot, and GitHub models, which will help it reach more enterprise applications. Users can access o3-mini for free in ChatGPT by choosing the ‘Reason’ option in the chat bar, but there are some usage limits.