OpenAI o3 vs Claude Opus 4.7 on Hard Problems

By C.W. Jameson · Published 15 November 2025 · Last reviewed 15 November 2025

o3 wins on competition math. Opus wins on long-horizon code. For everything else, the answer depends on the specific task more than the model.

Head-to-head on 20 hard reasoning, coding, and analysis tasks. Where each model wins and why.