Claude Sonnet 4.5 Pro vs Grok 4 Turbo: which model should you choose?
We compared Claude Sonnet 4.5 Pro and Grok 4 Turbo on price, context window and 12 benchmarks. Claude Sonnet 4.5 Pro and Grok 4 Turbo are effectively tied on the index average; 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
Grok 4 Turbo
Grok 4 Turbo is a frontier model from xAI. It offers a 1,000,000-token context window, costs $19.21 per million input tokens and $87.37 per million output tokens, and averages 86.7 across the index's benchmark suite.
- Input
- $19.21 / 1M
- Output
- $87.37 / 1M
- Context
- 1,000,000
- Avg score
- 86.7
- Open weights
- No
Specification comparison
| Spec | Claude Sonnet 4.5 Pro | Grok 4 Turbo | Edge |
|---|---|---|---|
| Input price / 1M | $18.73 | $19.21 | A |
| Output price / 1M | $82.29 | $87.37 | A |
| Context window | 1,000,000 | 1,000,000 | Tie |
| Max output | 16,384 | 65,536 | B |
| Average score | 86.7 | 86.7 | Tie |
| Arena Elo | 1469.0 | 1466.9 | A |
| Open weights | No | No | Tie |
Benchmark comparison
Claude Sonnet 4.5 Pro wins 7, Grok 4 Turbo wins 5, and 0 benchmarks are tied. The table shows the modelled score for each model and the gap.
| Benchmark | Claude Sonnet 4.5 Pro | Grok 4 Turbo | Gap | Winner |
|---|---|---|---|---|
| MMLU-Pro | 86.3 | 86.1 | 0.2 | Claude Sonnet 4.5 Pro |
| GPQA Diamond | 83.1 | 84.5 | 1.4 | Grok 4 Turbo |
| SWE-bench Verified | 73.9 | 73.8 | 0.1 | Claude Sonnet 4.5 Pro |
| HumanEval | 92.7 | 92.9 | 0.2 | Grok 4 Turbo |
| MATH-500 | 90.1 | 92.1 | 2.0 | Grok 4 Turbo |
| AIME 2025 | 88.4 | 85.2 | 3.2 | Claude Sonnet 4.5 Pro |
| LiveCodeBench | 81.9 | 84.7 | 2.8 | Grok 4 Turbo |
| IFEval | 94.1 | 91.1 | 3.0 | Claude Sonnet 4.5 Pro |
| TruthfulQA | 86.1 | 88.8 | 2.7 | Grok 4 Turbo |
| HellaSwag | 92.6 | 92.5 | 0.1 | Claude Sonnet 4.5 Pro |
| MMMU | 84.5 | 81.7 | 2.8 | Claude Sonnet 4.5 Pro |
| Arena Elo | 1469.0 | 1466.9 | 2.1 | Claude Sonnet 4.5 Pro |
Price analysis
On a blended 3:1 input-to-output basis, Claude Sonnet 4.5 Pro costs about $34.62 per million tokens and Grok 4 Turbo costs about $36.25. Claude Sonnet 4.5 Pro is roughly 4% cheaper than Grok 4 Turbo. 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 7, Grok 4 Turbo wins 5, and 0 are tied. The two models are effectively tied on the index average at 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 Claude Sonnet 4.5 Pro; it is cheaper on a blended basis and has the larger context window. Test it on your own traffic before committing.
Choose Claude Sonnet 4.5 Pro if
- Unit cost matters and you want the cheaper blended price.
Choose Grok 4 Turbo if
- You need the larger 65,536-token output limit.
FAQ
Is Claude Sonnet 4.5 Pro better than Grok 4 Turbo?
The two models are effectively tied on the index average at 86.7. The better choice depends on price, context and your task. Claude Sonnet 4.5 Pro wins 7 benchmarks, Grok 4 Turbo wins 5.
Which is cheaper, Claude Sonnet 4.5 Pro or Grok 4 Turbo?
Claude Sonnet 4.5 Pro is cheaper on a blended 3:1 basis at about $34.62 per million tokens, versus $36.25 for Grok 4 Turbo.
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; Grok 4 Turbo is proprietary.
Which should I choose for production?
If you need a single default, start with Claude Sonnet 4.5 Pro; it is cheaper on a blended basis and has the larger context window. Test it on your own traffic before committing.