Gemini 3.1 Pro Preview vs GPT-5.4 Mini

Across our 12‑test suite (internal scores), the matchup is mostly a tie: 9 tests tie, Gemini wins 2, GPT wins 1. Ties: structured_output (5/5 both; tied for 1st of 54), strategic_analysis (5/5 both; tied for 1st of 54), constrained_rewriting (4/4 both; rank 6/53), tool_calling (4/4 both; rank 18/54), faithfulness (5/5 both; tied for 1st of 55), long_context (5/5 both; tied for 1st of 55), safety_calibration (2/2 both; rank 12/55), persona_consistency (5/5 both; tied for 1st of 53), and multilingual (5/5 both; tied for 1st of 55). Gemini wins creative_problem_solving 5 vs 4 (Gemini ranks tied for 1st; GPT ranks 9/54) and agentic_planning 5 vs 4 (Gemini tied for 1st; GPT rank 16/54) — this implies Gemini is stronger at non‑obvious idea generation and robust goal decomposition/failure recovery in our tests. GPT-5.4 Mini wins classification 4 vs 2 (GPT tied for 1st of 53; Gemini ranks 51/53), so GPT is meaningfully better for routing/tagging tasks in our benchmarks. External supplement: Gemini scores 95.6% on AIME 2025 (Epoch AI) and ranks 2 of 23 on that external math benchmark—evidence of strong competition‑level math performance. In practice: expect parity on schema adherence, long contexts, multilingual output and faithfulness; prefer Gemini for creativity and agentic planners; prefer GPT-5.4 Mini for classification-heavy or cost-sensitive pipelines.

Payload prices: Gemini 3.1 Pro Preview input $2/MTok and output $12/MTok; GPT-5.4 Mini input $0.75/MTok and output $4.50/MTok. Interpreting mTok as 1,000 tokens, per‑1M tokens costs are: Gemini input $2,000 + output $12,000 = $14,000; GPT input $750 + output $4,500 = $5,250. At 10M tokens/month those totals scale to $140,000 vs $52,500; at 100M tokens/month to $1,400,000 vs $525,000. The output price ratio (Gemini/GPT) is ~2.67x (matches payload priceRatio). Who should care: high‑throughput businesses, real‑time chat providers, and cost‑sensitive startups—GPT-5.4 Mini can cut recurring token bills by ~60% for the same throughput. Teams that need Gemini’s specific wins (creative problem solving, agentic planning) or its 1,048,576 token context should budget for the higher cost.

Choose Gemini 3.1 Pro Preview if you need best-in-suite creative problem solving and agentic planning in our tests, require the very large 1,048,576‑token context window, or value the highest AIME math result (95.6% on AIME 2025, Epoch AI) — and you can absorb roughly 2.67x higher output cost. Choose GPT-5.4 Mini if you need a lower‑cost, high‑throughput API with parity across structured output, long context, multilingual and faithfulness tests and superior classification (4 vs Gemini’s 2 in our testing).