Gemini 2.5 Pro vs Gemini 3.1 Pro preview
Gemini 2.5 Pro vs Gemini 3.1 Pro preview: Gemini 2.5 Pro is cheaper by 38% on average. Gemini 2.5 Pro from Google Vertex AI (1,048,576-token context, reasoning, tool calls) vs. Gemini 3.1 Pro preview from Google Vertex AI (1,048,576-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
065,536
5,000
01,000,000
At this workload, Gemini 2.5 Pro is 28% cheaper than Gemini 3.1 Pro preview — a savings of $464/month ($5,570/year).
Production recipe — Agent Command Center
strategy: cost-optimized
primary:
model: gemini-2-5-pro
provider: vertex-ai
fallback:
model: gemini-3-1-pro-preview
provider: vertex-ai
shadow: { sample_rate: 0.05 } # mirror 5% of traffic to compare quality live| Gemini 2.5 Pro | Gemini 3.1 Pro preview | |
|---|---|---|
| Input price | $1.25/M | $2.00/M |
| Output price | $10.00/M | $12.00/M |
| Context window | 1,048,576 | 1,048,576 |
| Max output | 65,535 | 65,536 |
| 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 2.5 Pro
1,448
Gemini 3.1 Pro preview
1,492
GPQA Diamondreasoning⚠ different settings
Gemini 2.5 Pro
84.0%
Gemini 3.1 Pro preview
94.3%
SWE-bench Verifiedagent⚠ different settings
Gemini 2.5 Pro
63.8%
Gemini 3.1 Pro preview
80.6%
Humanity's Last Examreasoning⚠ different settings
Gemini 2.5 Pro
18.8%
Gemini 3.1 Pro preview
44.4%