Verdict
o3 leads 19–4 across 23 shared benchmarks.
o3 19 · o4-mini 4 · higher isn't always better — check the caveats below.
Reported scores — protocols may differ. How we compare
Reasoning: o3 leads 5–0 across 5 shared reasoning benchmarks (largest gap: SimpleQA Verified, 49.4 vs 19.6 — protocols undisclosed).
Unknown: o3 leads 4–0 across 4 shared unknown benchmarks (largest gap: Mystery Game Puzzles, 21.79 vs 0 — protocols undisclosed).
Math: Evenly split 1–1 across 2 shared math benchmarks (largest gap: OTIS Mock AIME 2024-2025, 84.43 vs 81.65 — single evaluator).
o3 leads 19–4 across 23 shared benchmarks. o3 leads 19 benchmarks and o4-mini leads 4. Higher isn't always better — see the integrity caveats on each benchmark.
o3 and o4-mini have 23 benchmarks in common in our data — those are the only rows where a direct, apples-to-apples comparison is drawn.
o3 leads reasoning 5–0. o3 leads unknown 4–0.