Verdict
GPT-6 Astra leads 13–1 across 15 shared benchmarks.
Claude Opus 5 1 · GPT-6 Astra 13 · 1 tied · higher isn't always better — check the caveats below.
Reported scores — protocols may differ. How we compare
Reasoning: GPT-6 Astra leads 3–0 across 3 shared reasoning benchmarks (largest gap: SimpleQA Verified, 75.6 vs 59.9 — protocols undisclosed).
Unknown: GPT-6 Astra leads 2–0 across 3 shared unknown benchmarks (largest gap: EBR-bench, 76.19 vs 45.71 — protocols undisclosed).
Coding: Evenly split 1–1 across 2 shared coding benchmarks (largest gap: DeepSWE, 74.12 vs 73.65 — single evaluator).
Math: GPT-6 Astra leads 2–0 across 2 shared math benchmarks (largest gap: FrontierMath-Tier-4-v2-Private, 97.6 vs 73.17 — protocols undisclosed).
GPT-6 Astra leads 13–1 across 15 shared benchmarks. Claude Opus 5 leads 1 benchmark and GPT-6 Astra leads 13, with 1 tied. Higher isn't always better — see the integrity caveats on each benchmark.
Claude Opus 5 and GPT-6 Astra have 15 benchmarks in common in our data — those are the only rows where a direct, apples-to-apples comparison is drawn.
GPT-6 Astra leads reasoning 3–0. GPT-6 Astra leads unknown 2–0.