OpenAI CEO Sam Altman teased exactly two weeks ago that o3-mini would ship in “a couple of weeks,” and it’s arriving on time today. OpenAI is launching its latest o3-mini reasoning model inside ChatGPT and its API services and making a version with rate limits available to free users of ChatGPT for the first time.

Originally announced as part of OpenAI’s 12 days of “ship-mas” in December, o3-mini is designed to match o1’s performance in math, coding, and science, while responding faster than the existing reasoning model. OpenAI says o3-mini should respond 24 percent faster than o1-mini and provide more accurate answers in the process. Much like o1-mini, this latest model will show how it worked out an answer, rather than just providing a response.

OpenAI provided some early benchmarks showing its o3 model outperforming o1 in December, and it now says the o3-mini version will outperform o1 in a number of coding and reasoning tasks at less cost and latency. Developers will be able to leverage o3-mini through OpenAI’s API services, including the Chat Completions API, Assistants API, and Batch API.

Paid users also be able to select o3-mini-high, which OpenAI says will be the “best coding option in ChatGPT” and include higher intelligence responses that take a little longer to generate. o3-mini will also work with search to find answers with links to web sources.

This is also the first time free users of ChatGPT will be able to try out OpenAI’s reasoning models, just days after Microsoft made o1 free for all Copilot users. You can try o3-mini free of charge in ChatGPT by selecting the Reason feature in the chat bar, and the rate limits will be similar to the existing GPT-4o limits. o3-mini will also be available for ChatGPT Plus, Team, and Pro users worldwide today, and OpenAI is tripling its message limits for Plus and Teams users to 150 messages per day. Only Pro users, who are willing to pay $200 a month, will get unlimited access to o3-mini.