Claude 3.5 Sonnet latest vs Gemini 3.1 Pro preview

Name: Gemini 3.1 Pro preview
Brand: Google Vertex AI
Price: 2.000000 USD

Claude 3.5 Sonnet latest vs Gemini 3.1 Pro preview: Gemini 3.1 Pro preview is cheaper by 33% on average. Claude 3.5 Sonnet latest from Anthropic (200,000-token context, 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.

Input tokens / request3,000

01,048,576

Output tokens / request400

065,536

Requests / day5,000

01,000,000

Claude 3.5 Sonnet latest

Anthropic

$2,283/mo

Input $3.00/M · Output $15.00/M

Gemini 3.1 Pro previewCheaper

Google Vertex AI

$1,644/mo

Input $2.00/M · Output $12.00/M

At this workload, Gemini 3.1 Pro preview is 28% cheaper than Claude 3.5 Sonnet latest — a savings of $639/month ($7,670/year).

Production recipe — Agent Command Center

strategy: cost-optimized
primary:
  model: gemini-3-1-pro-preview
  provider: vertex-ai
fallback:
  model: claude-3-5-sonnet-latest
  provider: anthropic
shadow: { sample_rate: 0.05 }   # mirror 5% of traffic to compare quality live

Get started free →Routing docs ↗

	Claude 3.5 Sonnet latest Anthropic	Gemini 3.1 Pro preview Google Vertex AI
Input price	$3.00/M	$2.00/M
Output price	$15.00/M	$12.00/M
Context window	200,000	1,048,576
Max output	8,192	65,536
Function calling	✓	✓
Vision	✓	✓
Audio input	—	✓
Reasoning	—	✓
Prompt caching	✓	✓
Structured output	✓	✓
Pricing verified	May 7, 2026	May 12, 2026