Head-to-head · frontier vs frontier

Claude Sonnet 4.5 Vision vs Gemini 2.5 Pro Pro: which model should you choose?

We compared Claude Sonnet 4.5 Vision and Gemini 2.5 Pro Pro on price, context window and 12 benchmarks. Claude Sonnet 4.5 Vision has the stronger average benchmark score; Claude Sonnet 4.5 Vision is cheaper on a blended 3:1 basis.

Anthropic

Claude Sonnet 4.5 Vision

Claude Sonnet 4.5 Vision is a frontier model from Anthropic. It offers a 128,000-token context window, costs $16.99 per million input tokens and $82.33 per million output tokens, and averages 83.8 across the index's benchmark suite.

Input
$16.99 / 1M
Output
$82.33 / 1M
Context
128,000
Avg score
83.8
Open weights
No
Full Claude Sonnet 4.5 Vision page
Google DeepMind

Gemini 2.5 Pro Pro

Gemini 2.5 Pro Pro is a frontier model from Google DeepMind. It offers a 400,000-token context window, costs $17.16 per million input tokens and $90.89 per million output tokens, and averages 83.6 across the index's benchmark suite.

Input
$17.16 / 1M
Output
$90.89 / 1M
Context
400,000
Avg score
83.6
Open weights
No
Full Gemini 2.5 Pro Pro page

Specification comparison

SpecClaude Sonnet 4.5 VisionGemini 2.5 Pro ProEdge
Input price / 1M$16.99$17.16A
Output price / 1M$82.33$90.89A
Context window128,000400,000B
Max output16,3848,192A
Average score83.883.6A
Arena Elo1447.61460.2B
Open weightsNoNoTie

Benchmark comparison

Claude Sonnet 4.5 Vision wins 4, Gemini 2.5 Pro Pro wins 7, and 1 benchmarks are tied. The table shows the modelled score for each model and the gap.

BenchmarkClaude Sonnet 4.5 VisionGemini 2.5 Pro ProGapWinner
MMLU-Pro84.885.20.4Gemini 2.5 Pro Pro
GPQA Diamond79.681.62.0Gemini 2.5 Pro Pro
SWE-bench Verified73.772.11.6Claude Sonnet 4.5 Vision
HumanEval87.088.41.4Gemini 2.5 Pro Pro
MATH-50090.686.83.8Claude Sonnet 4.5 Vision
AIME 202586.483.33.1Claude Sonnet 4.5 Vision
LiveCodeBench76.576.50.0Tie
IFEval89.992.02.1Gemini 2.5 Pro Pro
TruthfulQA83.785.51.8Gemini 2.5 Pro Pro
HellaSwag89.490.61.2Gemini 2.5 Pro Pro
MMMU79.778.11.6Claude Sonnet 4.5 Vision
Arena Elo1447.61460.212.6Gemini 2.5 Pro Pro

Price analysis

On a blended 3:1 input-to-output basis, Claude Sonnet 4.5 Vision costs about $33.33 per million tokens and Gemini 2.5 Pro Pro costs about $35.59. Claude Sonnet 4.5 Vision is roughly 6% cheaper than Gemini 2.5 Pro Pro. At high volume, that gap compounds quickly, so price should carry real weight unless the quality difference is decisive.

Gemini 2.5 Pro Pro has the larger context window at 400,000 tokens, compared with 128,000 for Claude Sonnet 4.5 Vision. That matters for long documents, large codebases and multi-step agent traces.

Verdict

Across 12 shared benchmarks, Claude Sonnet 4.5 Vision wins 4, Gemini 2.5 Pro Pro wins 7, and 1 are tied. On the index average, Claude Sonnet 4.5 Vision leads Gemini 2.5 Pro Pro by 0.2 points (83.8 versus 83.6).

The price picture favours Claude Sonnet 4.5 Vision. The context picture favours Gemini 2.5 Pro Pro. Those two dimensions often matter more than a few benchmark points once a model is good enough for the task.

If you need a single default, start with Claude Sonnet 4.5 Vision for quality-sensitive work, and check whether its price holds at your expected volume before committing.

Choose Claude Sonnet 4.5 Vision if

  • You want the higher average benchmark score in this index.
  • Unit cost matters and you want the cheaper blended price.
  • You need the larger 16,384-token output limit.

Choose Gemini 2.5 Pro Pro if

  • You need the larger 400,000-token context window.

FAQ

Is Claude Sonnet 4.5 Vision better than Gemini 2.5 Pro Pro?

On the index average, Claude Sonnet 4.5 Vision leads Gemini 2.5 Pro Pro by 0.2 points (83.8 versus 83.6). The better choice depends on price, context and your task. Claude Sonnet 4.5 Vision wins 4 benchmarks, Gemini 2.5 Pro Pro wins 7.

Which is cheaper, Claude Sonnet 4.5 Vision or Gemini 2.5 Pro Pro?

Claude Sonnet 4.5 Vision is cheaper on a blended 3:1 basis at about $33.33 per million tokens, versus $35.59 for Gemini 2.5 Pro Pro.

Which has the larger context window?

Gemini 2.5 Pro Pro has the larger context window at 400,000 tokens. Claude Sonnet 4.5 Vision has 128,000 tokens.

Are these models open weights?

Claude Sonnet 4.5 Vision is proprietary; Gemini 2.5 Pro Pro is proprietary.

Which should I choose for production?

If you need a single default, start with Claude Sonnet 4.5 Vision for quality-sensitive work, and check whether its price holds at your expected volume before committing.

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