Claude Sonnet 4.5 Pro vs GPT-5.2 Vision: which model should you choose?
We compared Claude Sonnet 4.5 Pro and GPT-5.2 Vision on price, context window and 12 benchmarks. GPT-5.2 Vision has the stronger average benchmark score; Claude Sonnet 4.5 Pro is cheaper on a blended 3:1 basis.
Claude Sonnet 4.5 Pro
Claude Sonnet 4.5 Pro is a frontier model from Anthropic. It offers a 1,000,000-token context window, costs $18.73 per million input tokens and $82.29 per million output tokens, and averages 86.7 across the index's benchmark suite.
- Input
- $18.73 / 1M
- Output
- $82.29 / 1M
- Context
- 1,000,000
- Avg score
- 86.7
- Open weights
- No
GPT-5.2 Vision
GPT-5.2 Vision is a frontier model from OpenAI. It offers a 1,000,000-token context window, costs $19.03 per million input tokens and $85.72 per million output tokens, and averages 87.4 across the index's benchmark suite.
- Input
- $19.03 / 1M
- Output
- $85.72 / 1M
- Context
- 1,000,000
- Avg score
- 87.4
- Open weights
- No
Specification comparison
| Spec | Claude Sonnet 4.5 Pro | GPT-5.2 Vision | Edge |
|---|---|---|---|
| Input price / 1M | $18.73 | $19.03 | A |
| Output price / 1M | $82.29 | $85.72 | A |
| Context window | 1,000,000 | 1,000,000 | Tie |
| Max output | 16,384 | 16,384 | Tie |
| Average score | 86.7 | 87.4 | B |
| Arena Elo | 1469.0 | 1484.3 | B |
| Open weights | No | No | Tie |
Benchmark comparison
Claude Sonnet 4.5 Pro wins 6, GPT-5.2 Vision wins 6, and 0 benchmarks are tied. The table shows the modelled score for each model and the gap.
| Benchmark | Claude Sonnet 4.5 Pro | GPT-5.2 Vision | Gap | Winner |
|---|---|---|---|---|
| MMLU-Pro | 86.3 | 89.5 | 3.2 | GPT-5.2 Vision |
| GPQA Diamond | 83.1 | 82.1 | 1.0 | Claude Sonnet 4.5 Pro |
| SWE-bench Verified | 73.9 | 78.8 | 4.9 | GPT-5.2 Vision |
| HumanEval | 92.7 | 91.2 | 1.5 | Claude Sonnet 4.5 Pro |
| MATH-500 | 90.1 | 92.9 | 2.8 | GPT-5.2 Vision |
| AIME 2025 | 88.4 | 85.7 | 2.7 | Claude Sonnet 4.5 Pro |
| LiveCodeBench | 81.9 | 83.4 | 1.5 | GPT-5.2 Vision |
| IFEval | 94.1 | 93.9 | 0.2 | Claude Sonnet 4.5 Pro |
| TruthfulQA | 86.1 | 85.3 | 0.8 | Claude Sonnet 4.5 Pro |
| HellaSwag | 92.6 | 94.6 | 2.0 | GPT-5.2 Vision |
| MMMU | 84.5 | 84.4 | 0.1 | Claude Sonnet 4.5 Pro |
| Arena Elo | 1469.0 | 1484.3 | 15.3 | GPT-5.2 Vision |
Price analysis
On a blended 3:1 input-to-output basis, Claude Sonnet 4.5 Pro costs about $34.62 per million tokens and GPT-5.2 Vision costs about $35.70. Claude Sonnet 4.5 Pro is roughly 3% cheaper than GPT-5.2 Vision. At high volume, that gap compounds quickly, so price should carry real weight unless the quality difference is decisive.
Both models list a 1,000,000-token context window. That is enough for long documents, large codebases and multi-step agent traces.
Verdict
Across 12 shared benchmarks, Claude Sonnet 4.5 Pro wins 6, GPT-5.2 Vision wins 6, and 0 are tied. On the index average, GPT-5.2 Vision leads Claude Sonnet 4.5 Pro by 0.7 points (87.4 versus 86.7).
The price picture favours Claude Sonnet 4.5 Pro. 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 GPT-5.2 Vision for quality-sensitive work and Claude Sonnet 4.5 Pro 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 Pro if
- Unit cost matters and you want the cheaper blended price.
Choose GPT-5.2 Vision if
- You want the higher average benchmark score in this index.
FAQ
Is Claude Sonnet 4.5 Pro better than GPT-5.2 Vision?
On the index average, GPT-5.2 Vision leads Claude Sonnet 4.5 Pro by 0.7 points (87.4 versus 86.7). The better choice depends on price, context and your task. Claude Sonnet 4.5 Pro wins 6 benchmarks, GPT-5.2 Vision wins 6.
Which is cheaper, Claude Sonnet 4.5 Pro or GPT-5.2 Vision?
Claude Sonnet 4.5 Pro is cheaper on a blended 3:1 basis at about $34.62 per million tokens, versus $35.70 for GPT-5.2 Vision.
Which has the larger context window?
Both models list a 1,000,000-token context window.
Are these models open weights?
Claude Sonnet 4.5 Pro is proprietary; GPT-5.2 Vision is proprietary.
Which should I choose for production?
If you need a single default, start with GPT-5.2 Vision for quality-sensitive work and Claude Sonnet 4.5 Pro for high-volume, well-scoped tasks. Run both on a sample of your own traffic before locking in a choice.