Claude Sonnet 4.5 Turbo vs Grok 4 Turbo: which model should you choose?
We compared Claude Sonnet 4.5 Turbo and Grok 4 Turbo on price, context window and 12 benchmarks. Grok 4 Turbo has the stronger average benchmark score; Claude Sonnet 4.5 Turbo is cheaper on a blended 3:1 basis.
Claude Sonnet 4.5 Turbo
Claude Sonnet 4.5 Turbo is a frontier model from Anthropic. It offers a 1,000,000-token context window, costs $18.37 per million input tokens and $81.65 per million output tokens, and averages 85.9 across the index's benchmark suite.
- Input
- $18.37 / 1M
- Output
- $81.65 / 1M
- Context
- 1,000,000
- Avg score
- 85.9
- 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 Turbo | Grok 4 Turbo | Edge |
|---|---|---|---|
| Input price / 1M | $18.37 | $19.21 | A |
| Output price / 1M | $81.65 | $87.37 | A |
| Context window | 1,000,000 | 1,000,000 | Tie |
| Max output | 65,536 | 65,536 | Tie |
| Average score | 85.9 | 86.7 | B |
| Arena Elo | 1461.7 | 1466.9 | B |
| Open weights | No | No | Tie |
Benchmark comparison
Claude Sonnet 4.5 Turbo wins 5, Grok 4 Turbo wins 7, and 0 benchmarks are tied. The table shows the modelled score for each model and the gap.
| Benchmark | Claude Sonnet 4.5 Turbo | Grok 4 Turbo | Gap | Winner |
|---|---|---|---|---|
| MMLU-Pro | 87.2 | 86.1 | 1.1 | Claude Sonnet 4.5 Turbo |
| GPQA Diamond | 83.7 | 84.5 | 0.8 | Grok 4 Turbo |
| SWE-bench Verified | 75.2 | 73.8 | 1.4 | Claude Sonnet 4.5 Turbo |
| HumanEval | 90.4 | 92.9 | 2.5 | Grok 4 Turbo |
| MATH-500 | 88.0 | 92.1 | 4.1 | Grok 4 Turbo |
| AIME 2025 | 87.8 | 85.2 | 2.6 | Claude Sonnet 4.5 Turbo |
| LiveCodeBench | 78.9 | 84.7 | 5.8 | Grok 4 Turbo |
| IFEval | 91.4 | 91.1 | 0.3 | Claude Sonnet 4.5 Turbo |
| TruthfulQA | 87.7 | 88.8 | 1.1 | Grok 4 Turbo |
| HellaSwag | 93.9 | 92.5 | 1.4 | Claude Sonnet 4.5 Turbo |
| MMMU | 81.1 | 81.7 | 0.6 | Grok 4 Turbo |
| Arena Elo | 1461.7 | 1466.9 | 5.2 | Grok 4 Turbo |
Price analysis
On a blended 3:1 input-to-output basis, Claude Sonnet 4.5 Turbo costs about $34.19 per million tokens and Grok 4 Turbo costs about $36.25. Claude Sonnet 4.5 Turbo is roughly 6% 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 Turbo wins 5, Grok 4 Turbo wins 7, and 0 are tied. On the index average, Grok 4 Turbo leads Claude Sonnet 4.5 Turbo by 0.8 points (86.7 versus 85.9).
The price picture favours Claude Sonnet 4.5 Turbo. 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 Grok 4 Turbo for quality-sensitive work and Claude Sonnet 4.5 Turbo for high-volume, well-scoped tasks. Run both on a sample of your own traffic before locking in a choice.
Choose Claude Sonnet 4.5 Turbo if
- Unit cost matters and you want the cheaper blended price.
Choose Grok 4 Turbo if
- You want the higher average benchmark score in this index.
FAQ
Is Claude Sonnet 4.5 Turbo better than Grok 4 Turbo?
On the index average, Grok 4 Turbo leads Claude Sonnet 4.5 Turbo by 0.8 points (86.7 versus 85.9). The better choice depends on price, context and your task. Claude Sonnet 4.5 Turbo wins 5 benchmarks, Grok 4 Turbo wins 7.
Which is cheaper, Claude Sonnet 4.5 Turbo or Grok 4 Turbo?
Claude Sonnet 4.5 Turbo is cheaper on a blended 3:1 basis at about $34.19 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 Turbo is proprietary; Grok 4 Turbo is proprietary.
Which should I choose for production?
If you need a single default, start with Grok 4 Turbo for quality-sensitive work and Claude Sonnet 4.5 Turbo for high-volume, well-scoped tasks. Run both on a sample of your own traffic before locking in a choice.