Across 22 shared benchmarks, Claude Sonnet 4.5 scores higher on 0 and GPT-6 Astra on 22. The widest gap is ARC-AGI-2, where GPT-6 Astra scores 95 against 13.6. Claude Sonnet 4.5 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 (anthropic-official, direct), otherwise the lowest tracked offer.