Gemini 3.1 Pro preview vs GPT-5 mini
Gemini 3.1 Pro preview vs GPT-5 mini: GPT-5 mini is cheaper by 88% on average. Gemini 3.1 Pro preview from Google Vertex AI (1,048,576-token context, reasoning, tool calls) vs. GPT-5 mini from OpenAI (272,000-token context, reasoning, tool calls). Use Agent Command Center to A/B both in shadow mode and pick the winner per workload.
Side-by-side cost
Live workload comparison
Same workload run through both models. The cheaper one is highlighted.
3,000
01,048,576
400
0128,000
5,000
01,000,000
At this workload, GPT-5 mini is 86% cheaper than Gemini 3.1 Pro preview — a savings of $1,408/month ($16,893/year).
Production recipe — Agent Command Center
strategy: cost-optimized
primary:
model: gpt-5-mini
provider: openai
fallback:
model: gemini-3-1-pro-preview
provider: vertex-ai
shadow: { sample_rate: 0.05 } # mirror 5% of traffic to compare quality live| Gemini 3.1 Pro preview | GPT-5 mini | |
|---|---|---|
| Input price | $2.00/M | $0.250/M |
| Output price | $12.00/M | $2.00/M |
| Context window | 1,048,576 | 272,000 |
| Max output | 65,536 | 128,000 |
| Function calling | ✓ | ✓ |
| Vision | ✓ | ✓ |
| Audio input | ✓ | — |
| Reasoning | ✓ | ✓ |
| Prompt caching | ✓ | ✓ |
| Structured output | ✓ | ✓ |
| Pricing verified | May 12, 2026 | May 12, 2026 |
Benchmark comparison
Side-by-side public benchmark scores. Greener bar = winner.
Chatbot Arena ELOgeneral
Gemini 3.1 Pro preview
1,492
GPT-5 mini
1,395
GPQA Diamondreasoning⚠ different settings
Gemini 3.1 Pro preview
94.3%
GPT-5 mini
78.4%
SWE-bench Verifiedagent⚠ different settings
Gemini 3.1 Pro preview
80.6%
GPT-5 mini
68.0%