Claude Opus 4.5 Vision vs o3 Reasoning: which model should you choose?
We compared Claude Opus 4.5 Vision and o3 Reasoning on price, context window and 12 benchmarks. Claude Opus 4.5 Vision has the stronger average benchmark score; o3 Reasoning 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
o3 Reasoning
o3 Reasoning is a frontier model from OpenAI. It offers a 200,000-token context window, costs $18.07 per million input tokens and $70.65 per million output tokens, and averages 85.3 across the index's benchmark suite.
- Input
- $18.07 / 1M
- Output
- $70.65 / 1M
- Context
- 200,000
- Avg score
- 85.3
- Open weights
- No
Specification comparison
| Spec | Claude Opus 4.5 Vision | o3 Reasoning | Edge |
|---|---|---|---|
| Input price / 1M | $17.70 | $18.07 | A |
| Output price / 1M | $74.84 | $70.65 | B |
| Context window | 200,000 | 200,000 | Tie |
| Max output | 32,768 | 16,384 | A |
| Average score | 85.9 | 85.3 | A |
| Arena Elo | 1452.2 | 1456.9 | B |
| Open weights | No | No | Tie |
Benchmark comparison
Claude Opus 4.5 Vision wins 7, o3 Reasoning 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 | o3 Reasoning | Gap | Winner |
|---|---|---|---|---|
| MMLU-Pro | 86.9 | 87.7 | 0.8 | o3 Reasoning |
| GPQA Diamond | 80.7 | 79.6 | 1.1 | Claude Opus 4.5 Vision |
| SWE-bench Verified | 77.7 | 74.1 | 3.6 | Claude Opus 4.5 Vision |
| HumanEval | 88.2 | 91.3 | 3.1 | o3 Reasoning |
| MATH-500 | 91.9 | 92.0 | 0.1 | o3 Reasoning |
| AIME 2025 | 85.4 | 80.5 | 4.9 | Claude Opus 4.5 Vision |
| LiveCodeBench | 80.1 | 82.7 | 2.6 | o3 Reasoning |
| IFEval | 92.6 | 90.6 | 2.0 | Claude Opus 4.5 Vision |
| TruthfulQA | 86.9 | 86.5 | 0.4 | Claude Opus 4.5 Vision |
| HellaSwag | 91.4 | 90.9 | 0.5 | Claude Opus 4.5 Vision |
| MMMU | 83.2 | 82.3 | 0.9 | Claude Opus 4.5 Vision |
| Arena Elo | 1452.2 | 1456.9 | 4.7 | o3 Reasoning |
Price analysis
On a blended 3:1 input-to-output basis, Claude Opus 4.5 Vision costs about $31.98 per million tokens and o3 Reasoning costs about $31.22. o3 Reasoning is roughly 2% cheaper than Claude Opus 4.5 Vision. At high volume, that gap compounds quickly, so price should carry real weight unless the quality difference is decisive.
Both models list a 200,000-token context window. That is enough for long documents, large codebases and multi-step agent traces.
Verdict
Across 12 shared benchmarks, Claude Opus 4.5 Vision wins 7, o3 Reasoning wins 5, and 0 are tied. On the index average, Claude Opus 4.5 Vision leads o3 Reasoning by 0.6 points (85.9 versus 85.3).
The price picture favours o3 Reasoning. The context picture is effectively a tie. 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 o3 Reasoning for high-volume, well-scoped tasks. Run both on a sample of your own traffic before locking in a choice.
Choose Claude Opus 4.5 Vision if
- You want the higher average benchmark score in this index.
- You need the larger 32,768-token output limit.
Choose o3 Reasoning if
- Unit cost matters and you want the cheaper blended price.
FAQ
Is Claude Opus 4.5 Vision better than o3 Reasoning?
On the index average, Claude Opus 4.5 Vision leads o3 Reasoning by 0.6 points (85.9 versus 85.3). The better choice depends on price, context and your task. Claude Opus 4.5 Vision wins 7 benchmarks, o3 Reasoning wins 5.
Which is cheaper, Claude Opus 4.5 Vision or o3 Reasoning?
o3 Reasoning is cheaper on a blended 3:1 basis at about $31.22 per million tokens, versus $31.98 for Claude Opus 4.5 Vision.
Which has the larger context window?
Both models list a 200,000-token context window.
Are these models open weights?
Claude Opus 4.5 Vision is proprietary; o3 Reasoning 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 o3 Reasoning for high-volume, well-scoped tasks. Run both on a sample of your own traffic before locking in a choice.