Head-to-head · frontier vs frontier

Claude Opus 4.5 Vision vs GPT-5.1 Vision: which model should you choose?

We compared Claude Opus 4.5 Vision and GPT-5.1 Vision on price, context window and 12 benchmarks. Claude Opus 4.5 Vision has the stronger average benchmark score; Claude Opus 4.5 Vision is cheaper on a blended 3:1 basis.

Anthropic

Claude Opus 4.5 Vision

Claude Opus 4.5 Vision is a frontier model from Anthropic. It offers a 200,000-token context window, costs $17.70 per million input tokens and $74.84 per million output tokens, and averages 85.9 across the index's benchmark suite.

Input
$17.70 / 1M
Output
$74.84 / 1M
Context
200,000
Avg score
85.9
Open weights
No
Full Claude Opus 4.5 Vision page
OpenAI

GPT-5.1 Vision

GPT-5.1 Vision is a frontier model from OpenAI. It offers a 400,000-token context window, costs $17.76 per million input tokens and $80.59 per million output tokens, and averages 84.8 across the index's benchmark suite.

Input
$17.76 / 1M
Output
$80.59 / 1M
Context
400,000
Avg score
84.8
Open weights
No
Full GPT-5.1 Vision page

Specification comparison

SpecClaude Opus 4.5 VisionGPT-5.1 VisionEdge
Input price / 1M$17.70$17.76A
Output price / 1M$74.84$80.59A
Context window200,000400,000B
Max output32,76816,384A
Average score85.984.8A
Arena Elo1452.21462.4B
Open weightsNoNoTie

Benchmark comparison

Claude Opus 4.5 Vision wins 6, GPT-5.1 Vision wins 5, and 1 benchmarks are tied. The table shows the modelled score for each model and the gap.

BenchmarkClaude Opus 4.5 VisionGPT-5.1 VisionGapWinner
MMLU-Pro86.985.51.4Claude Opus 4.5 Vision
GPQA Diamond80.778.72.0Claude Opus 4.5 Vision
SWE-bench Verified77.773.64.1Claude Opus 4.5 Vision
HumanEval88.289.61.4GPT-5.1 Vision
MATH-50091.989.12.8Claude Opus 4.5 Vision
AIME 202585.482.43.0Claude Opus 4.5 Vision
LiveCodeBench80.177.82.3Claude Opus 4.5 Vision
IFEval92.692.70.1GPT-5.1 Vision
TruthfulQA86.986.90.0Tie
HellaSwag91.492.10.7GPT-5.1 Vision
MMMU83.283.90.7GPT-5.1 Vision
Arena Elo1452.21462.410.2GPT-5.1 Vision

Price analysis

On a blended 3:1 input-to-output basis, Claude Opus 4.5 Vision costs about $31.98 per million tokens and GPT-5.1 Vision costs about $33.47. Claude Opus 4.5 Vision is roughly 4% cheaper than GPT-5.1 Vision. At high volume, that gap compounds quickly, so price should carry real weight unless the quality difference is decisive.

GPT-5.1 Vision has the larger context window at 400,000 tokens, compared with 200,000 for Claude Opus 4.5 Vision. That matters for long documents, large codebases and multi-step agent traces.

Verdict

Across 12 shared benchmarks, Claude Opus 4.5 Vision wins 6, GPT-5.1 Vision wins 5, and 1 are tied. On the index average, Claude Opus 4.5 Vision leads GPT-5.1 Vision by 1.1 points (85.9 versus 84.8).

The price picture favours Claude Opus 4.5 Vision. The context picture favours GPT-5.1 Vision. 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 Opus 4.5 Vision for quality-sensitive work, and check whether its price holds at your expected volume before committing.

Choose Claude Opus 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 32,768-token output limit.

Choose GPT-5.1 Vision if

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

FAQ

Is Claude Opus 4.5 Vision better than GPT-5.1 Vision?

On the index average, Claude Opus 4.5 Vision leads GPT-5.1 Vision by 1.1 points (85.9 versus 84.8). The better choice depends on price, context and your task. Claude Opus 4.5 Vision wins 6 benchmarks, GPT-5.1 Vision wins 5.

Which is cheaper, Claude Opus 4.5 Vision or GPT-5.1 Vision?

Claude Opus 4.5 Vision is cheaper on a blended 3:1 basis at about $31.98 per million tokens, versus $33.47 for GPT-5.1 Vision.

Which has the larger context window?

GPT-5.1 Vision has the larger context window at 400,000 tokens. Claude Opus 4.5 Vision has 200,000 tokens.

Are these models open weights?

Claude Opus 4.5 Vision is proprietary; GPT-5.1 Vision is proprietary.

Which should I choose for production?

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

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