GPT-4.1 Reasoning vs Grok 3 Pro: which model should you choose?
We compared GPT-4.1 Reasoning and Grok 3 Pro on price, context window and 12 benchmarks. GPT-4.1 Reasoning and Grok 3 Pro are effectively tied on the index average; Grok 3 Pro is cheaper on a blended 3:1 basis.
GPT-4.1 Reasoning
GPT-4.1 Reasoning is a frontier model from OpenAI. It offers a 1,000,000-token context window, costs $16.97 per million input tokens and $82.05 per million output tokens, and averages 83.8 across the index's benchmark suite.
- Input
- $16.97 / 1M
- Output
- $82.05 / 1M
- Context
- 1,000,000
- Avg score
- 83.8
- Open weights
- No
Grok 3 Pro
Grok 3 Pro is a frontier model from xAI. It offers a 400,000-token context window, costs $16.61 per million input tokens and $73.49 per million output tokens, and averages 83.8 across the index's benchmark suite.
- Input
- $16.61 / 1M
- Output
- $73.49 / 1M
- Context
- 400,000
- Avg score
- 83.8
- Open weights
- No
Specification comparison
| Spec | GPT-4.1 Reasoning | Grok 3 Pro | Edge |
|---|---|---|---|
| Input price / 1M | $16.97 | $16.61 | B |
| Output price / 1M | $82.05 | $73.49 | B |
| Context window | 1,000,000 | 400,000 | A |
| Max output | 4,096 | 4,096 | Tie |
| Average score | 83.8 | 83.8 | Tie |
| Arena Elo | 1466.7 | 1448.4 | A |
| Open weights | No | No | Tie |
Benchmark comparison
GPT-4.1 Reasoning wins 5, Grok 3 Pro wins 7, and 0 benchmarks are tied. The table shows the modelled score for each model and the gap.
| Benchmark | GPT-4.1 Reasoning | Grok 3 Pro | Gap | Winner |
|---|---|---|---|---|
| MMLU-Pro | 87.3 | 83.5 | 3.8 | GPT-4.1 Reasoning |
| GPQA Diamond | 77.8 | 81.3 | 3.5 | Grok 3 Pro |
| SWE-bench Verified | 73.1 | 71.4 | 1.7 | GPT-4.1 Reasoning |
| HumanEval | 88.8 | 89.9 | 1.1 | Grok 3 Pro |
| MATH-500 | 89.1 | 87.0 | 2.1 | GPT-4.1 Reasoning |
| AIME 2025 | 82.1 | 85.5 | 3.4 | Grok 3 Pro |
| LiveCodeBench | 80.5 | 80.7 | 0.2 | Grok 3 Pro |
| IFEval | 91.6 | 88.6 | 3.0 | GPT-4.1 Reasoning |
| TruthfulQA | 84.3 | 84.6 | 0.3 | Grok 3 Pro |
| HellaSwag | 89.4 | 90.7 | 1.3 | Grok 3 Pro |
| MMMU | 77.5 | 78.9 | 1.4 | Grok 3 Pro |
| Arena Elo | 1466.7 | 1448.4 | 18.3 | GPT-4.1 Reasoning |
Price analysis
On a blended 3:1 input-to-output basis, GPT-4.1 Reasoning costs about $33.24 per million tokens and Grok 3 Pro costs about $30.83. Grok 3 Pro is roughly 7% cheaper than GPT-4.1 Reasoning. At high volume, that gap compounds quickly, so price should carry real weight unless the quality difference is decisive.
GPT-4.1 Reasoning has the larger context window at 1,000,000 tokens, compared with 400,000 for Grok 3 Pro. That matters for long documents, large codebases and multi-step agent traces.
Verdict
Across 12 shared benchmarks, GPT-4.1 Reasoning wins 5, Grok 3 Pro wins 7, and 0 are tied. The two models are effectively tied on the index average at 83.8.
The price picture favours Grok 3 Pro. The context picture favours GPT-4.1 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 Grok 3 Pro if cost is the constraint and GPT-4.1 Reasoning if context is the constraint. Test both on a sample of your own traffic before committing.
Choose GPT-4.1 Reasoning if
- You need the larger 1,000,000-token context window.
Choose Grok 3 Pro if
- Unit cost matters and you want the cheaper blended price.
FAQ
Is GPT-4.1 Reasoning better than Grok 3 Pro?
The two models are effectively tied on the index average at 83.8. The better choice depends on price, context and your task. GPT-4.1 Reasoning wins 5 benchmarks, Grok 3 Pro wins 7.
Which is cheaper, GPT-4.1 Reasoning or Grok 3 Pro?
Grok 3 Pro is cheaper on a blended 3:1 basis at about $30.83 per million tokens, versus $33.24 for GPT-4.1 Reasoning.
Which has the larger context window?
GPT-4.1 Reasoning has the larger context window at 1,000,000 tokens. Grok 3 Pro has 400,000 tokens.
Are these models open weights?
GPT-4.1 Reasoning is proprietary; Grok 3 Pro is proprietary.
Which should I choose for production?
If you need a single default, start with Grok 3 Pro if cost is the constraint and GPT-4.1 Reasoning if context is the constraint. Test both on a sample of your own traffic before committing.