Claude Opus 4.5 Vision vs Gemini 3 Flash Pro: which model should you choose?
We compared Claude Opus 4.5 Vision and Gemini 3 Flash Pro 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.
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
Gemini 3 Flash Pro
Gemini 3 Flash Pro is a frontier model from Google DeepMind. It offers a 400,000-token context window, costs $17.71 per million input tokens and $86.50 per million output tokens, and averages 84.8 across the index's benchmark suite.
- Input
- $17.71 / 1M
- Output
- $86.50 / 1M
- Context
- 400,000
- Avg score
- 84.8
- Open weights
- No
Specification comparison
| Spec | Claude Opus 4.5 Vision | Gemini 3 Flash Pro | Edge |
|---|---|---|---|
| Input price / 1M | $17.70 | $17.71 | A |
| Output price / 1M | $74.84 | $86.50 | A |
| Context window | 200,000 | 400,000 | B |
| Max output | 32,768 | 4,096 | A |
| Average score | 85.9 | 84.8 | A |
| Arena Elo | 1452.2 | 1469.2 | B |
| Open weights | No | No | Tie |
Benchmark comparison
Claude Opus 4.5 Vision wins 7, Gemini 3 Flash Pro wins 5, and 0 benchmarks are tied. The table shows the modelled score for each model and the gap.
| Benchmark | Claude Opus 4.5 Vision | Gemini 3 Flash Pro | Gap | Winner |
|---|---|---|---|---|
| MMLU-Pro | 86.9 | 87.0 | 0.1 | Gemini 3 Flash Pro |
| GPQA Diamond | 80.7 | 77.7 | 3.0 | Claude Opus 4.5 Vision |
| SWE-bench Verified | 77.7 | 73.3 | 4.4 | Claude Opus 4.5 Vision |
| HumanEval | 88.2 | 89.9 | 1.7 | Gemini 3 Flash Pro |
| MATH-500 | 91.9 | 91.8 | 0.1 | Claude Opus 4.5 Vision |
| AIME 2025 | 85.4 | 79.9 | 5.5 | Claude Opus 4.5 Vision |
| LiveCodeBench | 80.1 | 80.2 | 0.1 | Gemini 3 Flash Pro |
| IFEval | 92.6 | 92.8 | 0.2 | Gemini 3 Flash Pro |
| TruthfulQA | 86.9 | 86.2 | 0.7 | Claude Opus 4.5 Vision |
| HellaSwag | 91.4 | 90.6 | 0.8 | Claude Opus 4.5 Vision |
| MMMU | 83.2 | 83.0 | 0.2 | Claude Opus 4.5 Vision |
| Arena Elo | 1452.2 | 1469.2 | 17.0 | Gemini 3 Flash Pro |
Price analysis
On a blended 3:1 input-to-output basis, Claude Opus 4.5 Vision costs about $31.98 per million tokens and Gemini 3 Flash Pro costs about $34.91. Claude Opus 4.5 Vision is roughly 8% cheaper than Gemini 3 Flash Pro. At high volume, that gap compounds quickly, so price should carry real weight unless the quality difference is decisive.
Gemini 3 Flash Pro 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 7, Gemini 3 Flash Pro wins 5, and 0 are tied. On the index average, Claude Opus 4.5 Vision leads Gemini 3 Flash Pro by 1.1 points (85.9 versus 84.8).
The price picture favours Claude Opus 4.5 Vision. The context picture favours Gemini 3 Flash 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 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 Gemini 3 Flash Pro if
- You need the larger 400,000-token context window.
FAQ
Is Claude Opus 4.5 Vision better than Gemini 3 Flash Pro?
On the index average, Claude Opus 4.5 Vision leads Gemini 3 Flash Pro 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 7 benchmarks, Gemini 3 Flash Pro wins 5.
Which is cheaper, Claude Opus 4.5 Vision or Gemini 3 Flash Pro?
Claude Opus 4.5 Vision is cheaper on a blended 3:1 basis at about $31.98 per million tokens, versus $34.91 for Gemini 3 Flash Pro.
Which has the larger context window?
Gemini 3 Flash Pro 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; Gemini 3 Flash Pro 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.