Across 27 shared benchmarks, Gemini 3.1 Pro scores higher on 8 and Gemini 3.8 Flash on 19. The widest gap is DeepSWE 1.1, where Gemini 3.8 Flash scores 73.7 against 12. Gemini 3.8 Flash is the cheaper of the two on tracked API pricing ($0.75 against $2.00 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 (google-official, google-official), otherwise the lowest tracked offer.