Gemini 3.1 Pro Preview vs Ministral 3 8B 2512

Summary of our 12-test suite (scores are from our testing):

• Gemini wins (8 tests): structured_output 5 vs 4 (Gemini tied 1st of 54, tied with 24), strategic_analysis 5 vs 3 (Gemini tied 1st of 54), creative_problem_solving 5 vs 3 (Gemini tied 1st), faithfulness 5 vs 4 (Gemini tied 1st of 55), long_context 5 vs 4 (Gemini tied 1st of 55), safety_calibration 2 vs 1 (Gemini rank 12 of 55), agentic_planning 5 vs 3 (Gemini tied 1st of 54), multilingual 5 vs 4 (Gemini tied 1st of 55). These wins mean Gemini is measurably stronger for JSON schema compliance, nuanced tradeoff reasoning, long‑context retrieval (30K+ tokens), resisting hallucination and goal decomposition in our tests.
• Ministral wins (2 tests): constrained_rewriting 5 vs 4 (Ministral tied for 1st of 53) and classification 4 vs 2 (Ministral tied for 1st of 53). This indicates Ministral is better at tight character‑limit compression and straightforward categorization/routing tasks in our testing.
• Ties (2 tests): tool_calling 4 vs 4 (tie; both rank 18 of 54) and persona_consistency 5 vs 5 (tie for 1st with many models). Practically, both handle function selection and persona retention similarly in our suite.
• External benchmark note: on AIME 2025 (Epoch AI), Gemini scores 95.6% (in our payload) and ranks 2 of 23 by that external measure — useful evidence for high numeric reasoning in competitive math tasks. Interpretation: Gemini is the higher‑quality, higher‑ranked model across most strategic and faithfulness dimensions; Ministral is focused value with specific strengths in constrained rewriting and classification. Choose based on whether accuracy on complex, long, multimodal workflows (Gemini) or token‑efficient, low‑cost classification/compression tasks (Ministral) is the priority.

Pricing (per 1,000 tokens): Gemini input $2 + output $12 = $14/mTok; Ministral input $0.15 + output $0.15 = $0.30/mTok. At 1M tokens/month (1,000 mTok) that is $14,000/mo for Gemini vs $300/mo for Ministral; at 10M: $140,000 vs $3,000; at 100M: $1,400,000 vs $30,000. The payload also records an output price ratio of 80x (Gemini $12 vs Ministral $0.15). Teams with high volume or tight margins must consider Ministral to avoid six‑figure/month bills; teams prioritizing top-tier reasoning, long context, multimodal workflows and willing to pay should consider Gemini despite the large cost gap.

Choose Gemini 3.1 Pro Preview if you need top-tier reasoning, long-context recall, faithfulness and multimodal reach (context window 1,048,576; modality: text+image+file+audio+video->text) and can absorb higher costs. Choose Ministral 3 8B 2512 if you must minimize per-token spend (input+output $0.30/mTok vs Gemini $14/mTok), and your workloads emphasize classification or constrained rewriting, or you operate at high token volumes where cost dominates.