Claude Opus 4.5 Pro vs Claude Opus 4.5 Reasoning: which model should you choose?
We compared Claude Opus 4.5 Pro and Claude Opus 4.5 Reasoning on price, context window and 12 benchmarks. Claude Opus 4.5 Pro has the stronger average benchmark score; Claude Opus 4.5 Pro is cheaper on a blended 3:1 basis.
Claude Opus 4.5 Pro
Claude Opus 4.5 Pro is a frontier model from Anthropic. It offers a 200,000-token context window, costs $20.98 per million input tokens and $85.59 per million output tokens, and averages 89.1 across the index's benchmark suite.
- Input
- $20.98 / 1M
- Output
- $85.59 / 1M
- Context
- 200,000
- Avg score
- 89.1
- Open weights
- No
Claude Opus 4.5 Reasoning
Claude Opus 4.5 Reasoning is a frontier model from Anthropic. It offers a 2,000,000-token context window, costs $20.91 per million input tokens and $108.13 per million output tokens, and averages 88.2 across the index's benchmark suite.
- Input
- $20.91 / 1M
- Output
- $108.13 / 1M
- Context
- 2,000,000
- Avg score
- 88.2
- Open weights
- No
Specification comparison
| Spec | Claude Opus 4.5 Pro | Claude Opus 4.5 Reasoning | Edge |
|---|---|---|---|
| Input price / 1M | $20.98 | $20.91 | B |
| Output price / 1M | $85.59 | $108.13 | A |
| Context window | 200,000 | 2,000,000 | B |
| Max output | 32,768 | 16,384 | A |
| Average score | 89.1 | 88.2 | A |
| Arena Elo | 1483.9 | 1497.5 | B |
| Open weights | No | No | Tie |
Benchmark comparison
Claude Opus 4.5 Pro wins 8, Claude Opus 4.5 Reasoning wins 4, and 0 benchmarks are tied. The table shows the modelled score for each model and the gap.
| Benchmark | Claude Opus 4.5 Pro | Claude Opus 4.5 Reasoning | Gap | Winner |
|---|---|---|---|---|
| MMLU-Pro | 91.2 | 90.7 | 0.5 | Claude Opus 4.5 Pro |
| GPQA Diamond | 86.0 | 82.6 | 3.4 | Claude Opus 4.5 Pro |
| SWE-bench Verified | 81.1 | 79.5 | 1.6 | Claude Opus 4.5 Pro |
| HumanEval | 93.4 | 92.1 | 1.3 | Claude Opus 4.5 Pro |
| MATH-500 | 91.2 | 91.6 | 0.4 | Claude Opus 4.5 Reasoning |
| AIME 2025 | 91.4 | 88.9 | 2.5 | Claude Opus 4.5 Pro |
| LiveCodeBench | 84.1 | 81.8 | 2.3 | Claude Opus 4.5 Pro |
| IFEval | 96.1 | 95.9 | 0.2 | Claude Opus 4.5 Pro |
| TruthfulQA | 86.7 | 89.0 | 2.3 | Claude Opus 4.5 Reasoning |
| HellaSwag | 95.2 | 93.8 | 1.4 | Claude Opus 4.5 Pro |
| MMMU | 83.3 | 84.6 | 1.3 | Claude Opus 4.5 Reasoning |
| Arena Elo | 1483.9 | 1497.5 | 13.6 | Claude Opus 4.5 Reasoning |
Price analysis
On a blended 3:1 input-to-output basis, Claude Opus 4.5 Pro costs about $37.13 per million tokens and Claude Opus 4.5 Reasoning costs about $42.72. Claude Opus 4.5 Pro is roughly 13% cheaper than Claude Opus 4.5 Reasoning. At high volume, that gap compounds quickly, so price should carry real weight unless the quality difference is decisive.
Claude Opus 4.5 Reasoning has the larger context window at 2,000,000 tokens, compared with 200,000 for Claude Opus 4.5 Pro. That matters for long documents, large codebases and multi-step agent traces.
Verdict
Across 12 shared benchmarks, Claude Opus 4.5 Pro wins 8, Claude Opus 4.5 Reasoning wins 4, and 0 are tied. On the index average, Claude Opus 4.5 Pro leads Claude Opus 4.5 Reasoning by 0.9 points (89.1 versus 88.2).
The price picture favours Claude Opus 4.5 Pro. The context picture favours Claude Opus 4.5 Reasoning. 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 Pro for quality-sensitive work, and check whether its price holds at your expected volume before committing.
Choose Claude Opus 4.5 Pro 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 Claude Opus 4.5 Reasoning if
- You need the larger 2,000,000-token context window.
FAQ
Is Claude Opus 4.5 Pro better than Claude Opus 4.5 Reasoning?
On the index average, Claude Opus 4.5 Pro leads Claude Opus 4.5 Reasoning by 0.9 points (89.1 versus 88.2). The better choice depends on price, context and your task. Claude Opus 4.5 Pro wins 8 benchmarks, Claude Opus 4.5 Reasoning wins 4.
Which is cheaper, Claude Opus 4.5 Pro or Claude Opus 4.5 Reasoning?
Claude Opus 4.5 Pro is cheaper on a blended 3:1 basis at about $37.13 per million tokens, versus $42.72 for Claude Opus 4.5 Reasoning.
Which has the larger context window?
Claude Opus 4.5 Reasoning has the larger context window at 2,000,000 tokens. Claude Opus 4.5 Pro has 200,000 tokens.
Are these models open weights?
Claude Opus 4.5 Pro is proprietary; Claude Opus 4.5 Reasoning is proprietary.
Which should I choose for production?
If you need a single default, start with Claude Opus 4.5 Pro for quality-sensitive work, and check whether its price holds at your expected volume before committing.