Weights aren’t public. Use is governed by OpenAI’s terms. Specs from models.dev, last changed Oct 19, 2026. Official source: platform.openai.com.
How good is it?
Public leaderboard scores for o3-pro, refreshed daily from Epoch AI and LMArena.
76Quality
Top 24% of the 277 models on the Epoch Capabilities Index: #68.
Quality is the share of a leaderboard’s models this one beats, from 0 to 100. Chat models are rated on Epoch AI’s Capabilities Index when it lists them, otherwise on LMArena; image and video models on LMArena’s image and video arenas.
One number fitted from dozens of hard benchmarks, from science questions to agentic coding.147.4 index
Scores from Epoch AI, licensed CC BY 4.0. Boards list models under their own names, so a close match is shown with the name it was scored under. Credits
Where to run it
9 providers sell o3-pro through an API. Prices are per million tokens, cheapest first.