OpenAI Brings Latest Reasoning Model to ChatGPT Free

Today, OpenAI released o3-mini, the latest and most cost-effective AI model in its reasoning series, and made it available via ChatGPT Free. This marks the first time an OpenAI reasoning model was made available to users of its free tier, and it follows the addition of OpenAI o1–an earlier reasoning model–to Microsoft’s ChatGPT.

“OpenAI o3-mini is a powerful and fast model that 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,” OpenAI explains in the announcement post. “While OpenAI o1 remains our broader general knowledge reasoning model, OpenAI o3-mini provides a specialized alternative for technical domains requiring precision and speed. In ChatGPT, o3-mini uses medium reasoning effort to provide a balanced trade-off between speed and accuracy.”

Reasoning models are AI models that are optimized for finite data sets with strong rules, and they usually display the rational for how they arrive at answers in real-time. In doing so, they appear to think about questions and then work through the problem.

OpenAI o1 was that company’s first series of reasoning models, with o1-mini being its first small language model (SML) for reasoning. O3-mini doesn’t support vision capabilities, like o1. But OpenAI says o3-mini matches o1 in certain capabilities while offering a 24 percent performance improvement over o1-mini. It also supports features like function calling, Structured Outputs, and developer messages that were requested by developers, which OpenAI says make o3-mini immediately production ready.

You can test OpenAI o1-mini preset to a medium reasoning effort in ChatGPT Free, Pro, Team, and Plus by selecting the “Reason” button below the Message box. This will cause ChatGPT to “think before responding.” If you have a paid ChatGPT subscription, o3-mini will replace o1-mini in the model picker soon, and as part of this upgrade, OpenAI is tripling the rate limit for Plus and Team users from 50 messages per day with o1-mini to 150 messages per day with o3-mini.