Gemini 3 Pro Reasoning vs Grok 4 Reasoning: which model should you choose?
We compared Gemini 3 Pro Reasoning and Grok 4 Reasoning on price, context window and 12 benchmarks. Grok 4 Reasoning has the stronger average benchmark score; Grok 4 Reasoning is cheaper on a blended 3:1 basis.
Gemini 3 Pro Reasoning
Gemini 3 Pro Reasoning is a frontier model from Google DeepMind. It offers a 200,000-token context window, costs $19.69 per million input tokens and $98.36 per million output tokens, and averages 87.5 across the index's benchmark suite.
- Input
- $19.69 / 1M
- Output
- $98.36 / 1M
- Context
- 200,000
- Avg score
- 87.5
- 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 | Gemini 3 Pro Reasoning | Grok 4 Reasoning | Edge |
|---|---|---|---|
| Input price / 1M | $19.69 | $19.67 | B |
| Output price / 1M | $98.36 | $93.29 | B |
| Context window | 200,000 | 2,000,000 | B |
| Max output | 8,192 | 65,536 | B |
| Average score | 87.5 | 87.8 | B |
| Arena Elo | 1485.0 | 1487.6 | B |
| Open weights | No | No | Tie |
Benchmark comparison
Gemini 3 Pro Reasoning wins 5, Grok 4 Reasoning wins 6, and 1 benchmarks are tied. The table shows the modelled score for each model and the gap.
| Benchmark | Gemini 3 Pro Reasoning | Grok 4 Reasoning | Gap | Winner |
|---|---|---|---|---|
| MMLU-Pro | 90.1 | 88.5 | 1.6 | Gemini 3 Pro Reasoning |
| GPQA Diamond | 83.9 | 81.9 | 2.0 | Gemini 3 Pro Reasoning |
| SWE-bench Verified | 76.3 | 78.0 | 1.7 | Grok 4 Reasoning |
| HumanEval | 90.2 | 93.8 | 3.6 | Grok 4 Reasoning |
| MATH-500 | 93.3 | 94.4 | 1.1 | Grok 4 Reasoning |
| AIME 2025 | 88.8 | 85.6 | 3.2 | Gemini 3 Pro Reasoning |
| LiveCodeBench | 82.0 | 85.1 | 3.1 | Grok 4 Reasoning |
| IFEval | 93.8 | 93.4 | 0.4 | Gemini 3 Pro Reasoning |
| TruthfulQA | 90.3 | 89.4 | 0.9 | Gemini 3 Pro Reasoning |
| HellaSwag | 93.5 | 95.2 | 1.7 | Grok 4 Reasoning |
| MMMU | 80.8 | 80.8 | 0.0 | Tie |
| Arena Elo | 1485.0 | 1487.6 | 2.6 | Grok 4 Reasoning |
Price analysis
On a blended 3:1 input-to-output basis, Gemini 3 Pro Reasoning costs about $39.36 per million tokens and Grok 4 Reasoning costs about $38.08. Grok 4 Reasoning is roughly 3% cheaper than Gemini 3 Pro Reasoning. At high volume, that gap compounds quickly, so price should carry real weight unless the quality difference is decisive.
Grok 4 Reasoning has the larger context window at 2,000,000 tokens, compared with 200,000 for Gemini 3 Pro Reasoning. That matters for long documents, large codebases and multi-step agent traces.
Verdict
Across 12 shared benchmarks, Gemini 3 Pro Reasoning wins 5, Grok 4 Reasoning wins 6, and 1 are tied. On the index average, Grok 4 Reasoning leads Gemini 3 Pro Reasoning by 0.3 points (87.8 versus 87.5).
The price picture favours Grok 4 Reasoning. The context picture favours Grok 4 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 4 Reasoning for quality-sensitive work, and check whether its price holds at your expected volume before committing.
Choose Gemini 3 Pro Reasoning if
- You prefer Google DeepMind's tooling or already use it.
Choose Grok 4 Reasoning 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.
- You need the larger 65,536-token output limit.
FAQ
Is Gemini 3 Pro Reasoning better than Grok 4 Reasoning?
On the index average, Grok 4 Reasoning leads Gemini 3 Pro Reasoning by 0.3 points (87.8 versus 87.5). The better choice depends on price, context and your task. Gemini 3 Pro Reasoning wins 5 benchmarks, Grok 4 Reasoning wins 6.
Which is cheaper, Gemini 3 Pro Reasoning or Grok 4 Reasoning?
Grok 4 Reasoning is cheaper on a blended 3:1 basis at about $38.08 per million tokens, versus $39.36 for Gemini 3 Pro Reasoning.
Which has the larger context window?
Grok 4 Reasoning has the larger context window at 2,000,000 tokens. Gemini 3 Pro Reasoning has 200,000 tokens.
Are these models open weights?
Gemini 3 Pro Reasoning is proprietary; Grok 4 Reasoning is proprietary.
Which should I choose for production?
If you need a single default, start with Grok 4 Reasoning for quality-sensitive work, and check whether its price holds at your expected volume before committing.