Gemini 2.5 Flash vs Gemma 4 31B

Walkthrough of our 12-test suite (scores are from our testing). Wins: Gemma 4 31B wins five benchmarks: structured_output 5 vs 4 (Gemma tied for 1st on structured output), strategic_analysis 5 vs 3 (Gemma tied for 1st in strategic analysis), faithfulness 5 vs 4 (Gemma tied for 1st in faithfulness), classification 4 vs 3 (Gemma tied for 1st in classification), and agentic_planning 5 vs 4 (Gemma tied for 1st on agentic planning). Gemini 2.5 Flash wins two benchmarks: long_context 5 vs 4 (Gemini tied for 1st — critical for retrieval at 30K+ tokens) and safety_calibration 4 vs 2 (Gemini ranks 6 of 55 vs Gemma's rank 12). Five tests tie: constrained_rewriting (4/4), creative_problem_solving (4/4), tool_calling (5/5 — both tied for 1st), persona_consistency (5/5 — both tied for 1st), and multilingual (5/5 — both tied for 1st). What this means in practice: choose Gemma when you prioritize accurate structured outputs, nuance in multi-step reasoning and strict faithfulness to source material; choose Gemini when you need retrieval/analysis across very long documents or stronger safety refusal behavior. Rankings give context: Gemini’s long-context is tied for 1st out of 55 tested models, while Gemma ranks tied for 1st on strategic analysis and faithfulness across the same suite — these are not subjective claims but how they placed in our tests.

Payload prices: Gemini 2.5 Flash input $0.30 / mTok and output $2.50 / mTok; Gemma 4 31B input $0.13 / mTok and output $0.38 / mTok. Assuming mTok = 1,000 tokens (per-1K pricing), per 1M tokens (1,000 mTok) output-only cost is $2,500 (Gemini) vs $380 (Gemma). For a 50/50 input/output split per 1M tokens: Gemini ≈ $1,400 (0.3500 + 2.5500) vs Gemma ≈ $255 (0.13500 + 0.38500). Scale: at 10M tokens/month those become ~$14,000 vs ~$2,550; at 100M tokens/month ~$140,000 vs ~$25,500. The ~6.58× price ratio (2.5/0.38) means high-volume apps and consumer products should favor Gemma to control costs; teams that require Gemini's 1,048,576-token context window or its stronger safety calibration should budget for much higher per-token spend.

Choose Gemma 4 31B if you need the best mix of strategic analysis, faithfulness, structured output and classification at a much lower price per token (input $0.13 / mTok, output $0.38 / mTok). Choose Gemini 2.5 Flash if you require extreme long-context (1,048,576-token window), stronger safety calibration, or multimodal inputs including file/audio/video handling and you can absorb roughly a 6.6× higher per-output-token cost (Gemini output $2.50 / mTok).