Verdict
o3 leads 9–2 across 11 shared benchmarks.
Gemini 2.5 Pro (Mar 2025) 2 · o3 9 · higher isn't always better — check the caveats below.
Reported scores — protocols may differ. How we compare
Reasoning: o3 leads 3–1 across 4 shared reasoning benchmarks (largest gap: ARC-AGI, 60.8 vs 33 — single evaluator).
o3 leads 9–2 across 11 shared benchmarks. Gemini 2.5 Pro (Mar 2025) leads 2 benchmarks and o3 leads 9. Higher isn't always better — see the integrity caveats on each benchmark.
Gemini 2.5 Pro (Mar 2025) and o3 have 11 benchmarks in common in our data — those are the only rows where a direct, apples-to-apples comparison is drawn.
o3 leads reasoning 3–1.