Across 29 shared benchmarks, Claude Sonnet 4.6 scores higher on 3 and GPT-6 Astra on 26. The widest gap is AA-Omniscience, where GPT-6 Astra scores 43.7 against 12.2. Claude Sonnet 4.6 is the cheaper of the two on tracked API pricing ($3.00 against $10.00 per million input tokens).
Best tracked score per model per benchmark (default configuration; source-attributed). ↓ marks lower-is-better metrics. Open either model for its full surface, provenance and pricing. Quoted rates are the price-setter row we currently track for each model — its direct or vendor-official listing where one exists (direct, direct), otherwise the lowest tracked offer.