Verdict
Claude Opus 5.5 leads 9–2 across 13 shared benchmarks.
Claude Opus 5.5 9 · Claude Sonnet 5.5 2 · 2 tied · higher isn't always better — check the caveats below.
Reported scores — protocols may differ. How we compare
Unknown: Claude Opus 5.5 leads 3–0 across 4 shared unknown benchmarks (largest gap: Furniture Assembly, 76.19 vs 64.29 — protocols undisclosed).
Coding: Claude Opus 5.5 leads 2–0 across 2 shared coding benchmarks (largest gap: FrontierCode, 54.64 vs 52.09 — single evaluator).
Math: Claude Opus 5.5 leads 1–0 across 2 shared math benchmarks (largest gap: FrontierMath-Tier-4-v2-Private, 95 vs 80.49 — protocols undisclosed).
Reasoning: Evenly split 1–1 across 2 shared reasoning benchmarks (largest gap: SimpleQA Verified, 72.2 vs 46.5 — protocols undisclosed).
Claude Opus 5.5 leads 9–2 across 13 shared benchmarks. Claude Opus 5.5 leads 9 benchmarks and Claude Sonnet 5.5 leads 2, with 2 tied. Higher isn't always better — see the integrity caveats on each benchmark.
Claude Opus 5.5 and Claude Sonnet 5.5 have 13 benchmarks in common in our data — those are the only rows where a direct, apples-to-apples comparison is drawn.
Claude Opus 5.5 leads unknown 3–0. Claude Opus 5.5 leads coding 2–0.