Head-to-head · frontier vs frontier

Claude Opus 4.5 vs Grok 4 Turbo: which model should you choose?

We compared Claude Opus 4.5 and Grok 4 Turbo on price, context window and 12 benchmarks. Claude Opus 4.5 has the stronger average benchmark score; Claude Opus 4.5 is cheaper on a blended 3:1 basis.

Anthropic

Claude Opus 4.5

Claude Opus 4.5 is a frontier model from Anthropic. It offers a 400,000-token context window, costs $19.42 per million input tokens and $75.27 per million output tokens, and averages 87.7 across the index's benchmark suite.

Input
$19.42 / 1M
Output
$75.27 / 1M
Context
400,000
Avg score
87.7
Open weights
No
Full Claude Opus 4.5 page
xAI

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
Full Grok 4 Turbo page

Specification comparison

SpecClaude Opus 4.5Grok 4 TurboEdge
Input price / 1M$19.42$19.21B
Output price / 1M$75.27$87.37A
Context window400,0001,000,000B
Max output4,09665,536B
Average score87.786.7A
Arena Elo1491.21466.9A
Open weightsNoNoTie

Benchmark comparison

Claude Opus 4.5 wins 9, Grok 4 Turbo wins 3, and 0 benchmarks are tied. The table shows the modelled score for each model and the gap.

BenchmarkClaude Opus 4.5Grok 4 TurboGapWinner
MMLU-Pro87.086.10.9Claude Opus 4.5
GPQA Diamond81.784.52.8Grok 4 Turbo
SWE-bench Verified77.173.83.3Claude Opus 4.5
HumanEval93.792.90.8Claude Opus 4.5
MATH-50093.792.11.6Claude Opus 4.5
AIME 202589.885.24.6Claude Opus 4.5
LiveCodeBench85.084.70.3Claude Opus 4.5
IFEval92.591.11.4Claude Opus 4.5
TruthfulQA88.188.80.7Grok 4 Turbo
HellaSwag92.492.50.1Grok 4 Turbo
MMMU84.281.72.5Claude Opus 4.5
Arena Elo1491.21466.924.3Claude Opus 4.5

Price analysis

On a blended 3:1 input-to-output basis, Claude Opus 4.5 costs about $33.38 per million tokens and Grok 4 Turbo costs about $36.25. Claude Opus 4.5 is roughly 8% cheaper than Grok 4 Turbo. At high volume, that gap compounds quickly, so price should carry real weight unless the quality difference is decisive.

Grok 4 Turbo has the larger context window at 1,000,000 tokens, compared with 400,000 for Claude Opus 4.5. That matters for long documents, large codebases and multi-step agent traces.

Verdict

Across 12 shared benchmarks, Claude Opus 4.5 wins 9, Grok 4 Turbo wins 3, and 0 are tied. On the index average, Claude Opus 4.5 leads Grok 4 Turbo by 1.0 points (87.7 versus 86.7).

The price picture favours Claude Opus 4.5. The context picture favours Grok 4 Turbo. 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 Opus 4.5 for quality-sensitive work, and check whether its price holds at your expected volume before committing.

Choose Claude Opus 4.5 if

  • You want the higher average benchmark score in this index.
  • Unit cost matters and you want the cheaper blended price.

Choose Grok 4 Turbo if

  • You need the larger 1,000,000-token context window.
  • You need the larger 65,536-token output limit.

FAQ

Is Claude Opus 4.5 better than Grok 4 Turbo?

On the index average, Claude Opus 4.5 leads Grok 4 Turbo by 1.0 points (87.7 versus 86.7). The better choice depends on price, context and your task. Claude Opus 4.5 wins 9 benchmarks, Grok 4 Turbo wins 3.

Which is cheaper, Claude Opus 4.5 or Grok 4 Turbo?

Claude Opus 4.5 is cheaper on a blended 3:1 basis at about $33.38 per million tokens, versus $36.25 for Grok 4 Turbo.

Which has the larger context window?

Grok 4 Turbo has the larger context window at 1,000,000 tokens. Claude Opus 4.5 has 400,000 tokens.

Are these models open weights?

Claude Opus 4.5 is proprietary; Grok 4 Turbo is proprietary.

Which should I choose for production?

If you need a single default, start with Claude Opus 4.5 for quality-sensitive work, and check whether its price holds at your expected volume before committing.

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