Claude Opus 4.5 Pro vs GPT-5.2 Pro: which model should you choose?
We compared Claude Opus 4.5 Pro and GPT-5.2 Pro on price, context window and 12 benchmarks. GPT-5.2 Pro has the stronger average benchmark score; GPT-5.2 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
GPT-5.2 Pro
GPT-5.2 Pro is a frontier model from OpenAI. It offers a 2,000,000-token context window, costs $21.32 per million input tokens and $76.33 per million output tokens, and averages 89.6 across the index's benchmark suite.
- Input
- $21.32 / 1M
- Output
- $76.33 / 1M
- Context
- 2,000,000
- Avg score
- 89.6
- Open weights
- No
Specification comparison
| Spec | Claude Opus 4.5 Pro | GPT-5.2 Pro | Edge |
|---|---|---|---|
| Input price / 1M | $20.98 | $21.32 | A |
| Output price / 1M | $85.59 | $76.33 | B |
| Context window | 200,000 | 2,000,000 | B |
| Max output | 32,768 | 32,768 | Tie |
| Average score | 89.1 | 89.6 | B |
| Arena Elo | 1483.9 | 1485.0 | B |
| Open weights | No | No | Tie |
Benchmark comparison
Claude Opus 4.5 Pro wins 3, GPT-5.2 Pro wins 9, and 0 benchmarks are tied. The table shows the modelled score for each model and the gap.
| Benchmark | Claude Opus 4.5 Pro | GPT-5.2 Pro | Gap | Winner |
|---|---|---|---|---|
| MMLU-Pro | 91.2 | 91.6 | 0.4 | GPT-5.2 Pro |
| GPQA Diamond | 86.0 | 83.2 | 2.8 | Claude Opus 4.5 Pro |
| SWE-bench Verified | 81.1 | 81.7 | 0.6 | GPT-5.2 Pro |
| HumanEval | 93.4 | 96.8 | 3.4 | GPT-5.2 Pro |
| MATH-500 | 91.2 | 91.8 | 0.6 | GPT-5.2 Pro |
| AIME 2025 | 91.4 | 91.0 | 0.4 | Claude Opus 4.5 Pro |
| LiveCodeBench | 84.1 | 84.6 | 0.5 | GPT-5.2 Pro |
| IFEval | 96.1 | 95.6 | 0.5 | Claude Opus 4.5 Pro |
| TruthfulQA | 86.7 | 90.0 | 3.3 | GPT-5.2 Pro |
| HellaSwag | 95.2 | 95.3 | 0.1 | GPT-5.2 Pro |
| MMMU | 83.3 | 84.4 | 1.1 | GPT-5.2 Pro |
| Arena Elo | 1483.9 | 1485.0 | 1.1 | GPT-5.2 Pro |
Price analysis
On a blended 3:1 input-to-output basis, Claude Opus 4.5 Pro costs about $37.13 per million tokens and GPT-5.2 Pro costs about $35.07. GPT-5.2 Pro is roughly 6% cheaper than Claude Opus 4.5 Pro. At high volume, that gap compounds quickly, so price should carry real weight unless the quality difference is decisive.
GPT-5.2 Pro 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 3, GPT-5.2 Pro wins 9, and 0 are tied. On the index average, GPT-5.2 Pro leads Claude Opus 4.5 Pro by 0.5 points (89.6 versus 89.1).
The price picture favours GPT-5.2 Pro. The context picture favours GPT-5.2 Pro. 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 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 prefer Anthropic's tooling or already use it.
Choose GPT-5.2 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 2,000,000-token context window.
FAQ
Is Claude Opus 4.5 Pro better than GPT-5.2 Pro?
On the index average, GPT-5.2 Pro leads Claude Opus 4.5 Pro by 0.5 points (89.6 versus 89.1). The better choice depends on price, context and your task. Claude Opus 4.5 Pro wins 3 benchmarks, GPT-5.2 Pro wins 9.
Which is cheaper, Claude Opus 4.5 Pro or GPT-5.2 Pro?
GPT-5.2 Pro is cheaper on a blended 3:1 basis at about $35.07 per million tokens, versus $37.13 for Claude Opus 4.5 Pro.
Which has the larger context window?
GPT-5.2 Pro 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; GPT-5.2 Pro is proprietary.
Which should I choose for production?
If you need a single default, start with GPT-5.2 Pro for quality-sensitive work, and check whether its price holds at your expected volume before committing.