Claude Opus 4.5 Vision vs Grok 4: which model should you choose?
We compared Claude Opus 4.5 Vision and Grok 4 on price, context window and 12 benchmarks. Grok 4 has the stronger average benchmark score; Claude Opus 4.5 Vision is cheaper on a blended 3:1 basis.
Claude Opus 4.5 Vision
Claude Opus 4.5 Vision is a frontier model from Anthropic. It offers a 200,000-token context window, costs $17.70 per million input tokens and $74.84 per million output tokens, and averages 85.9 across the index's benchmark suite.
- Input
- $17.70 / 1M
- Output
- $74.84 / 1M
- Context
- 200,000
- Avg score
- 85.9
- Open weights
- No
Grok 4
Grok 4 is a frontier model from xAI. It offers a 200,000-token context window, costs $17.90 per million input tokens and $84.75 per million output tokens, and averages 86.5 across the index's benchmark suite.
- Input
- $17.90 / 1M
- Output
- $84.75 / 1M
- Context
- 200,000
- Avg score
- 86.5
- Open weights
- No
Specification comparison
| Spec | Claude Opus 4.5 Vision | Grok 4 | Edge |
|---|---|---|---|
| Input price / 1M | $17.70 | $17.90 | A |
| Output price / 1M | $74.84 | $84.75 | A |
| Context window | 200,000 | 200,000 | Tie |
| Max output | 32,768 | 32,768 | Tie |
| Average score | 85.9 | 86.5 | B |
| Arena Elo | 1452.2 | 1457.8 | B |
| Open weights | No | No | Tie |
Benchmark comparison
Claude Opus 4.5 Vision wins 4, Grok 4 wins 8, and 0 benchmarks are tied. The table shows the modelled score for each model and the gap.
| Benchmark | Claude Opus 4.5 Vision | Grok 4 | Gap | Winner |
|---|---|---|---|---|
| MMLU-Pro | 86.9 | 87.8 | 0.9 | Grok 4 |
| GPQA Diamond | 80.7 | 82.6 | 1.9 | Grok 4 |
| SWE-bench Verified | 77.7 | 77.9 | 0.2 | Grok 4 |
| HumanEval | 88.2 | 92.0 | 3.8 | Grok 4 |
| MATH-500 | 91.9 | 90.8 | 1.1 | Claude Opus 4.5 Vision |
| AIME 2025 | 85.4 | 82.2 | 3.2 | Claude Opus 4.5 Vision |
| LiveCodeBench | 80.1 | 82.2 | 2.1 | Grok 4 |
| IFEval | 92.6 | 91.6 | 1.0 | Claude Opus 4.5 Vision |
| TruthfulQA | 86.9 | 87.6 | 0.7 | Grok 4 |
| HellaSwag | 91.4 | 93.9 | 2.5 | Grok 4 |
| MMMU | 83.2 | 82.9 | 0.3 | Claude Opus 4.5 Vision |
| Arena Elo | 1452.2 | 1457.8 | 5.6 | Grok 4 |
Price analysis
On a blended 3:1 input-to-output basis, Claude Opus 4.5 Vision costs about $31.98 per million tokens and Grok 4 costs about $34.61. Claude Opus 4.5 Vision is roughly 8% cheaper than Grok 4. At high volume, that gap compounds quickly, so price should carry real weight unless the quality difference is decisive.
Both models list a 200,000-token context window. That is enough for long documents, large codebases and multi-step agent traces.
Verdict
Across 12 shared benchmarks, Claude Opus 4.5 Vision wins 4, Grok 4 wins 8, and 0 are tied. On the index average, Grok 4 leads Claude Opus 4.5 Vision by 0.6 points (86.5 versus 85.9).
The price picture favours Claude Opus 4.5 Vision. 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 for quality-sensitive work and Claude Opus 4.5 Vision for high-volume, well-scoped tasks. Run both on a sample of your own traffic before locking in a choice.
Choose Claude Opus 4.5 Vision if
- Unit cost matters and you want the cheaper blended price.
Choose Grok 4 if
- You want the higher average benchmark score in this index.
FAQ
Is Claude Opus 4.5 Vision better than Grok 4?
On the index average, Grok 4 leads Claude Opus 4.5 Vision by 0.6 points (86.5 versus 85.9). The better choice depends on price, context and your task. Claude Opus 4.5 Vision wins 4 benchmarks, Grok 4 wins 8.
Which is cheaper, Claude Opus 4.5 Vision or Grok 4?
Claude Opus 4.5 Vision is cheaper on a blended 3:1 basis at about $31.98 per million tokens, versus $34.61 for Grok 4.
Which has the larger context window?
Both models list a 200,000-token context window.
Are these models open weights?
Claude Opus 4.5 Vision is proprietary; Grok 4 is proprietary.
Which should I choose for production?
If you need a single default, start with Grok 4 for quality-sensitive work and Claude Opus 4.5 Vision for high-volume, well-scoped tasks. Run both on a sample of your own traffic before locking in a choice.