Claude Sonnet 4.5 (2025-09-29) vs Gemini 3 Pro Preview

Claude Sonnet 4.5 (2025-09-29) vs Gemini 3 Pro Preview: Gemini 3 Pro Preview is cheaper by 33% on average. Claude Sonnet 4.5 (2025-09-29) from Anthropic (200,000-token context, reasoning, tool calls) vs. Gemini 3 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
065,535
5,000
01,000,000
Anthropic
$2,283/mo
Input $3.00/M · Output $15.00/M
Google Vertex AI
$1,644/mo
Input $2.00/M · Output $12.00/M
At this workload, Gemini 3 Pro Preview is 28% cheaper than Claude Sonnet 4.5 (2025-09-29) — a savings of $639/month ($7,670/year).
Production recipe — Agent Command Center
strategy: cost-optimized
primary:
  model: gemini-3-pro-preview
  provider: vertex-ai
fallback:
  model: claude-sonnet-4-5-20250929
  provider: anthropic
shadow: { sample_rate: 0.05 }   # mirror 5% of traffic to compare quality live
Claude Sonnet 4.5 (2025-09-29) Gemini 3 Pro Preview
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 64,000 65,535
Function calling
Vision
Audio input
Reasoning
Prompt caching
Structured output
Pricing verified May 12, 2026 May 12, 2026
Cheaper option
~33% cheaper than Claude Sonnet 4.5 (2025-09-29)
Larger context
1,048,576 tokens
More capabilities
6 of 6 capability flags advertised

Benchmark comparison

Side-by-side public benchmark scores. Greener bar = winner.

Chatbot Arena ELOgeneral
Claude Sonnet 4.5 (2025-09-29)
1,454
Gemini 3 Pro Preview
1,486
AIME 2025math
Claude Sonnet 4.5 (2025-09-29)
100.0%
Gemini 3 Pro Preview
HumanEvalcode
Claude Sonnet 4.5 (2025-09-29)
93.7%
Gemini 3 Pro Preview
MATH-500math
Claude Sonnet 4.5 (2025-09-29)
88.0%
Gemini 3 Pro Preview
IFEvalgeneral
Claude Sonnet 4.5 (2025-09-29)
87.6%
Gemini 3 Pro Preview
MMLU-Proreasoning
Claude Sonnet 4.5 (2025-09-29)
87.4%
Gemini 3 Pro Preview
BFCL v3agent
Claude Sonnet 4.5 (2025-09-29)
85.7%
Gemini 3 Pro Preview
GPQA Diamondreasoning
Claude Sonnet 4.5 (2025-09-29)
84.4%
Gemini 3 Pro Preview
SWE-bench Verifiedagent
Claude Sonnet 4.5 (2025-09-29)
82.0%
Gemini 3 Pro Preview
AIME 2024math
Claude Sonnet 4.5 (2025-09-29)
79.6%
Gemini 3 Pro Preview
Aider Polyglotcode
Claude Sonnet 4.5 (2025-09-29)
77.8%
Gemini 3 Pro Preview
MMMUmultimodal
Claude Sonnet 4.5 (2025-09-29)
77.6%
Gemini 3 Pro Preview
τ-bench (retail)agent
Claude Sonnet 4.5 (2025-09-29)
75.4%
Gemini 3 Pro Preview
LiveCodeBenchcode
Claude Sonnet 4.5 (2025-09-29)
67.4%
Gemini 3 Pro Preview
τ-bench (airline)agent
Claude Sonnet 4.5 (2025-09-29)
55.0%
Gemini 3 Pro Preview