Claude Opus 4.5 Turbo vs Gemini 3 Pro Reasoning: which model should you choose?
We compared Claude Opus 4.5 Turbo and Gemini 3 Pro Reasoning on price, context window and 12 benchmarks. Gemini 3 Pro Reasoning has the stronger average benchmark score; Gemini 3 Pro Reasoning is cheaper on a blended 3:1 basis.
Claude Opus 4.5 Turbo
Claude Opus 4.5 Turbo is a frontier model from Anthropic. It offers a 2,000,000-token context window, costs $19.57 per million input tokens and $106.60 per million output tokens, and averages 85.7 across the index's benchmark suite.
- Input
- $19.57 / 1M
- Output
- $106.60 / 1M
- Context
- 2,000,000
- Avg score
- 85.7
- Open weights
- No
Gemini 3 Pro Reasoning
Gemini 3 Pro Reasoning is a frontier model from Google DeepMind. It offers a 200,000-token context window, costs $19.69 per million input tokens and $98.36 per million output tokens, and averages 87.5 across the index's benchmark suite.
- Input
- $19.69 / 1M
- Output
- $98.36 / 1M
- Context
- 200,000
- Avg score
- 87.5
- Open weights
- No
Specification comparison
| Spec | Claude Opus 4.5 Turbo | Gemini 3 Pro Reasoning | Edge |
|---|---|---|---|
| Input price / 1M | $19.57 | $19.69 | A |
| Output price / 1M | $106.60 | $98.36 | B |
| Context window | 2,000,000 | 200,000 | A |
| Max output | 65,536 | 8,192 | A |
| Average score | 85.7 | 87.5 | B |
| Arena Elo | 1469.3 | 1485.0 | B |
| Open weights | No | No | Tie |
Benchmark comparison
Claude Opus 4.5 Turbo wins 0, Gemini 3 Pro Reasoning wins 12, and 0 benchmarks are tied. The table shows the modelled score for each model and the gap.
| Benchmark | Claude Opus 4.5 Turbo | Gemini 3 Pro Reasoning | Gap | Winner |
|---|---|---|---|---|
| MMLU-Pro | 85.8 | 90.1 | 4.3 | Gemini 3 Pro Reasoning |
| GPQA Diamond | 81.9 | 83.9 | 2.0 | Gemini 3 Pro Reasoning |
| SWE-bench Verified | 75.0 | 76.3 | 1.3 | Gemini 3 Pro Reasoning |
| HumanEval | 89.8 | 90.2 | 0.4 | Gemini 3 Pro Reasoning |
| MATH-500 | 93.2 | 93.3 | 0.1 | Gemini 3 Pro Reasoning |
| AIME 2025 | 87.2 | 88.8 | 1.6 | Gemini 3 Pro Reasoning |
| LiveCodeBench | 78.5 | 82.0 | 3.5 | Gemini 3 Pro Reasoning |
| IFEval | 92.2 | 93.8 | 1.6 | Gemini 3 Pro Reasoning |
| TruthfulQA | 85.5 | 90.3 | 4.8 | Gemini 3 Pro Reasoning |
| HellaSwag | 92.8 | 93.5 | 0.7 | Gemini 3 Pro Reasoning |
| MMMU | 80.5 | 80.8 | 0.3 | Gemini 3 Pro Reasoning |
| Arena Elo | 1469.3 | 1485.0 | 15.7 | Gemini 3 Pro Reasoning |
Price analysis
On a blended 3:1 input-to-output basis, Claude Opus 4.5 Turbo costs about $41.33 per million tokens and Gemini 3 Pro Reasoning costs about $39.36. Gemini 3 Pro Reasoning is roughly 5% cheaper than Claude Opus 4.5 Turbo. At high volume, that gap compounds quickly, so price should carry real weight unless the quality difference is decisive.
Claude Opus 4.5 Turbo has the larger context window at 2,000,000 tokens, compared with 200,000 for Gemini 3 Pro Reasoning. That matters for long documents, large codebases and multi-step agent traces.
Verdict
Across 12 shared benchmarks, Claude Opus 4.5 Turbo wins 0, Gemini 3 Pro Reasoning wins 12, and 0 are tied. On the index average, Gemini 3 Pro Reasoning leads Claude Opus 4.5 Turbo by 1.8 points (87.5 versus 85.7).
The price picture favours Gemini 3 Pro Reasoning. The context picture favours Claude Opus 4.5 Turbo. 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 Gemini 3 Pro Reasoning for quality-sensitive work, and check whether its price holds at your expected volume before committing.
Choose Claude Opus 4.5 Turbo if
- You need the larger 2,000,000-token context window.
- You need the larger 65,536-token output limit.
Choose Gemini 3 Pro Reasoning if
- You want the higher average benchmark score in this index.
- Unit cost matters and you want the cheaper blended price.
FAQ
Is Claude Opus 4.5 Turbo better than Gemini 3 Pro Reasoning?
On the index average, Gemini 3 Pro Reasoning leads Claude Opus 4.5 Turbo by 1.8 points (87.5 versus 85.7). The better choice depends on price, context and your task. Claude Opus 4.5 Turbo wins 0 benchmarks, Gemini 3 Pro Reasoning wins 12.
Which is cheaper, Claude Opus 4.5 Turbo or Gemini 3 Pro Reasoning?
Gemini 3 Pro Reasoning is cheaper on a blended 3:1 basis at about $39.36 per million tokens, versus $41.33 for Claude Opus 4.5 Turbo.
Which has the larger context window?
Claude Opus 4.5 Turbo has the larger context window at 2,000,000 tokens. Gemini 3 Pro Reasoning has 200,000 tokens.
Are these models open weights?
Claude Opus 4.5 Turbo is proprietary; Gemini 3 Pro Reasoning is proprietary.
Which should I choose for production?
If you need a single default, start with Gemini 3 Pro Reasoning for quality-sensitive work, and check whether its price holds at your expected volume before committing.