Claude Sonnet 4.5 Vision vs o4 Vision: which model should you choose?
We compared Claude Sonnet 4.5 Vision and o4 Vision on price, context window and 12 benchmarks. o4 Vision has the stronger average benchmark score; Claude Sonnet 4.5 Vision is cheaper on a blended 3:1 basis.
Claude Sonnet 4.5 Vision
Claude Sonnet 4.5 Vision is a frontier model from Anthropic. It offers a 128,000-token context window, costs $16.99 per million input tokens and $82.33 per million output tokens, and averages 83.8 across the index's benchmark suite.
- Input
- $16.99 / 1M
- Output
- $82.33 / 1M
- Context
- 128,000
- Avg score
- 83.8
- Open weights
- No
o4 Vision
o4 Vision is a frontier model from OpenAI. It offers a 200,000-token context window, costs $17.01 per million input tokens and $90.05 per million output tokens, and averages 84.5 across the index's benchmark suite.
- Input
- $17.01 / 1M
- Output
- $90.05 / 1M
- Context
- 200,000
- Avg score
- 84.5
- Open weights
- No
Specification comparison
| Spec | Claude Sonnet 4.5 Vision | o4 Vision | Edge |
|---|---|---|---|
| Input price / 1M | $16.99 | $17.01 | A |
| Output price / 1M | $82.33 | $90.05 | A |
| Context window | 128,000 | 200,000 | B |
| Max output | 16,384 | 4,096 | A |
| Average score | 83.8 | 84.5 | B |
| Arena Elo | 1447.6 | 1473.2 | B |
| Open weights | No | No | Tie |
Benchmark comparison
Claude Sonnet 4.5 Vision wins 3, o4 Vision wins 9, and 0 benchmarks are tied. The table shows the modelled score for each model and the gap.
| Benchmark | Claude Sonnet 4.5 Vision | o4 Vision | Gap | Winner |
|---|---|---|---|---|
| MMLU-Pro | 84.8 | 84.2 | 0.6 | Claude Sonnet 4.5 Vision |
| GPQA Diamond | 79.6 | 80.9 | 1.3 | o4 Vision |
| SWE-bench Verified | 73.7 | 75.6 | 1.9 | o4 Vision |
| HumanEval | 87.0 | 88.9 | 1.9 | o4 Vision |
| MATH-500 | 90.6 | 91.7 | 1.1 | o4 Vision |
| AIME 2025 | 86.4 | 80.4 | 6.0 | Claude Sonnet 4.5 Vision |
| LiveCodeBench | 76.5 | 81.3 | 4.8 | o4 Vision |
| IFEval | 89.9 | 89.1 | 0.8 | Claude Sonnet 4.5 Vision |
| TruthfulQA | 83.7 | 85.3 | 1.6 | o4 Vision |
| HellaSwag | 89.4 | 91.2 | 1.8 | o4 Vision |
| MMMU | 79.7 | 80.7 | 1.0 | o4 Vision |
| Arena Elo | 1447.6 | 1473.2 | 25.6 | o4 Vision |
Price analysis
On a blended 3:1 input-to-output basis, Claude Sonnet 4.5 Vision costs about $33.33 per million tokens and o4 Vision costs about $35.27. Claude Sonnet 4.5 Vision is roughly 6% cheaper than o4 Vision. At high volume, that gap compounds quickly, so price should carry real weight unless the quality difference is decisive.
o4 Vision has the larger context window at 200,000 tokens, compared with 128,000 for Claude Sonnet 4.5 Vision. That matters for long documents, large codebases and multi-step agent traces.
Verdict
Across 12 shared benchmarks, Claude Sonnet 4.5 Vision wins 3, o4 Vision wins 9, and 0 are tied. On the index average, o4 Vision leads Claude Sonnet 4.5 Vision by 0.7 points (84.5 versus 83.8).
The price picture favours Claude Sonnet 4.5 Vision. The context picture favours o4 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 o4 Vision for quality-sensitive work and Claude Sonnet 4.5 Vision for high-volume, well-scoped tasks. Run both on a sample of your own traffic before locking in a choice.
Choose Claude Sonnet 4.5 Vision if
- Unit cost matters and you want the cheaper blended price.
- You need the larger 16,384-token output limit.
Choose o4 Vision if
- You want the higher average benchmark score in this index.
- You need the larger 200,000-token context window.
FAQ
Is Claude Sonnet 4.5 Vision better than o4 Vision?
On the index average, o4 Vision leads Claude Sonnet 4.5 Vision by 0.7 points (84.5 versus 83.8). The better choice depends on price, context and your task. Claude Sonnet 4.5 Vision wins 3 benchmarks, o4 Vision wins 9.
Which is cheaper, Claude Sonnet 4.5 Vision or o4 Vision?
Claude Sonnet 4.5 Vision is cheaper on a blended 3:1 basis at about $33.33 per million tokens, versus $35.27 for o4 Vision.
Which has the larger context window?
o4 Vision has the larger context window at 200,000 tokens. Claude Sonnet 4.5 Vision has 128,000 tokens.
Are these models open weights?
Claude Sonnet 4.5 Vision is proprietary; o4 Vision is proprietary.
Which should I choose for production?
If you need a single default, start with o4 Vision for quality-sensitive work and Claude Sonnet 4.5 Vision for high-volume, well-scoped tasks. Run both on a sample of your own traffic before locking in a choice.