Verdict
GPT-5.6 Sol leads 17–0 across 17 shared benchmarks.
Claude Opus 4.6 0 · GPT-5.6 Sol 17 · higher isn't always better — check the caveats below.
Reported scores — protocols may differ. How we compare
Unknown: GPT-5.6 Sol leads 5–0 across 5 shared unknown benchmarks (largest gap: Mystery Game Puzzles, 53.73 vs 17.38 — protocols undisclosed).
Reasoning: GPT-5.6 Sol leads 4–0 across 4 shared reasoning benchmarks (largest gap: SimpleQA Verified, 69.7 vs 47 — protocols undisclosed).
Math: GPT-5.6 Sol leads 2–0 across 2 shared math benchmarks (largest gap: FrontierMath-Tier-4-v2-Private, 82.93 vs 26.83 — single evaluator).
Vendor claims — compare against the measured scores above. A claim is what a developer says about its own model, not an independent measurement.
Coding
“The new Claude Opus 4.6 improves on its predecessor's coding skills”
No vendor claims on file for GPT-5.6 Sol.
GPT-5.6 Sol leads 17–0 across 17 shared benchmarks. Claude Opus 4.6 leads 0 benchmarks and GPT-5.6 Sol leads 17. Higher isn't always better — see the integrity caveats on each benchmark.
Claude Opus 4.6 and GPT-5.6 Sol have 17 benchmarks in common in our data — those are the only rows where a direct, apples-to-apples comparison is drawn.
GPT-5.6 Sol leads unknown 5–0. GPT-5.6 Sol leads reasoning 4–0.