OpenAI's high-compute reasoning model — more thinking time for the hardest problems in math, science, and code.
o3-pro is OpenAI's high-compute tier of the o3 reasoning model. It trades latency and cost for deeper chain-of-thought, making it the go-to for competition-level math, frontier research, and multi-step code reasoning where being right matters more than being fast. If o3 is the workhorse, o3-pro is the thoroughbred you bring out for the hardest problems.
Who it's for: Researchers, competition mathematicians, and senior engineers working on problems where a wrong answer costs more than a slow one.
Runs an extended chain-of-thought budget — the model thinks longer before answering, especially on math and logic.
Scores at the top of AIME, MATH-500, and Codeforces benchmarks — rivaling domain specialists.
Excels at multi-step proof, paper-style reasoning, and complex refactor tasks.
Reliable tool use even in long multi-step agent workflows.
o3-pro is a specialist, not a daily driver. If you're tackling competition math, frontier research, or multi-step code proofs, it's the sharpest tool available. For everyday writing, drafting, and chat, it's wasteful. Pair it with a cheaper model for routine work and reserve o3-pro for the problems that genuinely need the extra compute.