GPT-5.2 vs Grok 4 Reasoning: which model should you choose?
We compared GPT-5.2 and Grok 4 Reasoning on price, context window and 12 benchmarks. GPT-5.2 has the stronger average benchmark score; GPT-5.2 is cheaper on a blended 3:1 basis.
GPT-5.2
GPT-5.2 is a frontier model from OpenAI. It offers a 2,000,000-token context window, costs $19.71 per million input tokens and $85.71 per million output tokens, and averages 88.0 across the index's benchmark suite.
- Input
- $19.71 / 1M
- Output
- $85.71 / 1M
- Context
- 2,000,000
- Avg score
- 88.0
- Open weights
- No
Grok 4 Reasoning
Grok 4 Reasoning is a frontier model from xAI. It offers a 2,000,000-token context window, costs $19.67 per million input tokens and $93.29 per million output tokens, and averages 87.8 across the index's benchmark suite.
- Input
- $19.67 / 1M
- Output
- $93.29 / 1M
- Context
- 2,000,000
- Avg score
- 87.8
- Open weights
- No
Specification comparison
| Spec | GPT-5.2 | Grok 4 Reasoning | Edge |
|---|---|---|---|
| Input price / 1M | $19.71 | $19.67 | B |
| Output price / 1M | $85.71 | $93.29 | A |
| Context window | 2,000,000 | 2,000,000 | Tie |
| Max output | 16,384 | 65,536 | B |
| Average score | 88.0 | 87.8 | A |
| Arena Elo | 1478.0 | 1487.6 | B |
| Open weights | No | No | Tie |
Benchmark comparison
GPT-5.2 wins 7, Grok 4 Reasoning wins 5, and 0 benchmarks are tied. The table shows the modelled score for each model and the gap.
| Benchmark | GPT-5.2 | Grok 4 Reasoning | Gap | Winner |
|---|---|---|---|---|
| MMLU-Pro | 89.9 | 88.5 | 1.4 | GPT-5.2 |
| GPQA Diamond | 84.9 | 81.9 | 3.0 | GPT-5.2 |
| SWE-bench Verified | 80.2 | 78.0 | 2.2 | GPT-5.2 |
| HumanEval | 91.0 | 93.8 | 2.8 | Grok 4 Reasoning |
| MATH-500 | 90.6 | 94.4 | 3.8 | Grok 4 Reasoning |
| AIME 2025 | 90.6 | 85.6 | 5.0 | GPT-5.2 |
| LiveCodeBench | 79.7 | 85.1 | 5.4 | Grok 4 Reasoning |
| IFEval | 93.6 | 93.4 | 0.2 | GPT-5.2 |
| TruthfulQA | 89.7 | 89.4 | 0.3 | GPT-5.2 |
| HellaSwag | 92.6 | 95.2 | 2.6 | Grok 4 Reasoning |
| MMMU | 85.3 | 80.8 | 4.5 | GPT-5.2 |
| Arena Elo | 1478.0 | 1487.6 | 9.6 | Grok 4 Reasoning |
Price analysis
On a blended 3:1 input-to-output basis, GPT-5.2 costs about $36.21 per million tokens and Grok 4 Reasoning costs about $38.08. GPT-5.2 is roughly 5% cheaper than Grok 4 Reasoning. At high volume, that gap compounds quickly, so price should carry real weight unless the quality difference is decisive.
Both models list a 2,000,000-token context window. That is enough for long documents, large codebases and multi-step agent traces.
Verdict
Across 12 shared benchmarks, GPT-5.2 wins 7, Grok 4 Reasoning wins 5, and 0 are tied. On the index average, GPT-5.2 leads Grok 4 Reasoning by 0.2 points (88.0 versus 87.8).
The price picture favours GPT-5.2. 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 for quality-sensitive work, and check whether its price holds at your expected volume before committing.
Choose GPT-5.2 if
- You want the higher average benchmark score in this index.
- Unit cost matters and you want the cheaper blended price.
Choose Grok 4 Reasoning if
- You need the larger 65,536-token output limit.
FAQ
Is GPT-5.2 better than Grok 4 Reasoning?
On the index average, GPT-5.2 leads Grok 4 Reasoning by 0.2 points (88.0 versus 87.8). The better choice depends on price, context and your task. GPT-5.2 wins 7 benchmarks, Grok 4 Reasoning wins 5.
Which is cheaper, GPT-5.2 or Grok 4 Reasoning?
GPT-5.2 is cheaper on a blended 3:1 basis at about $36.21 per million tokens, versus $38.08 for Grok 4 Reasoning.
Which has the larger context window?
Both models list a 2,000,000-token context window.
Are these models open weights?
GPT-5.2 is proprietary; Grok 4 Reasoning is proprietary.
Which should I choose for production?
If you need a single default, start with GPT-5.2 for quality-sensitive work, and check whether its price holds at your expected volume before committing.