Head-to-head · frontier vs frontier

Claude 3.7 Sonnet Pro vs Grok 3 Pro: which model should you choose?

We compared Claude 3.7 Sonnet Pro and Grok 3 Pro on price, context window and 12 benchmarks. Grok 3 Pro has the stronger average benchmark score; Grok 3 Pro is cheaper on a blended 3:1 basis.

Anthropic

Claude 3.7 Sonnet Pro

Claude 3.7 Sonnet Pro is a frontier model from Anthropic. It offers a 128,000-token context window, costs $16.07 per million input tokens and $85.28 per million output tokens, and averages 83.3 across the index's benchmark suite.

Input
$16.07 / 1M
Output
$85.28 / 1M
Context
128,000
Avg score
83.3
Open weights
No
Full Claude 3.7 Sonnet Pro page
xAI

Grok 3 Pro

Grok 3 Pro is a frontier model from xAI. It offers a 400,000-token context window, costs $16.61 per million input tokens and $73.49 per million output tokens, and averages 83.8 across the index's benchmark suite.

Input
$16.61 / 1M
Output
$73.49 / 1M
Context
400,000
Avg score
83.8
Open weights
No
Full Grok 3 Pro page

Specification comparison

SpecClaude 3.7 Sonnet ProGrok 3 ProEdge
Input price / 1M$16.07$16.61A
Output price / 1M$85.28$73.49B
Context window128,000400,000B
Max output8,1924,096A
Average score83.383.8B
Arena Elo1446.81448.4B
Open weightsNoNoTie

Benchmark comparison

Claude 3.7 Sonnet Pro wins 5, Grok 3 Pro wins 6, and 1 benchmarks are tied. The table shows the modelled score for each model and the gap.

BenchmarkClaude 3.7 Sonnet ProGrok 3 ProGapWinner
MMLU-Pro85.783.52.2Claude 3.7 Sonnet Pro
GPQA Diamond80.681.30.7Grok 3 Pro
SWE-bench Verified71.471.40.0Tie
HumanEval90.089.90.1Claude 3.7 Sonnet Pro
MATH-50089.287.02.2Claude 3.7 Sonnet Pro
AIME 202581.585.54.0Grok 3 Pro
LiveCodeBench74.180.76.6Grok 3 Pro
IFEval88.588.60.1Grok 3 Pro
TruthfulQA86.084.61.4Claude 3.7 Sonnet Pro
HellaSwag89.790.71.0Grok 3 Pro
MMMU79.778.90.8Claude 3.7 Sonnet Pro
Arena Elo1446.81448.41.6Grok 3 Pro

Price analysis

On a blended 3:1 input-to-output basis, Claude 3.7 Sonnet Pro costs about $33.37 per million tokens and Grok 3 Pro costs about $30.83. Grok 3 Pro is roughly 8% cheaper than Claude 3.7 Sonnet Pro. At high volume, that gap compounds quickly, so price should carry real weight unless the quality difference is decisive.

Grok 3 Pro has the larger context window at 400,000 tokens, compared with 128,000 for Claude 3.7 Sonnet Pro. That matters for long documents, large codebases and multi-step agent traces.

Verdict

Across 12 shared benchmarks, Claude 3.7 Sonnet Pro wins 5, Grok 3 Pro wins 6, and 1 are tied. On the index average, Grok 3 Pro leads Claude 3.7 Sonnet Pro by 0.5 points (83.8 versus 83.3).

The price picture favours Grok 3 Pro. The context picture favours Grok 3 Pro. 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 3 Pro for quality-sensitive work, and check whether its price holds at your expected volume before committing.

Choose Claude 3.7 Sonnet Pro if

  • You need the larger 8,192-token output limit.

Choose Grok 3 Pro 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 400,000-token context window.

FAQ

Is Claude 3.7 Sonnet Pro better than Grok 3 Pro?

On the index average, Grok 3 Pro leads Claude 3.7 Sonnet Pro by 0.5 points (83.8 versus 83.3). The better choice depends on price, context and your task. Claude 3.7 Sonnet Pro wins 5 benchmarks, Grok 3 Pro wins 6.

Which is cheaper, Claude 3.7 Sonnet Pro or Grok 3 Pro?

Grok 3 Pro is cheaper on a blended 3:1 basis at about $30.83 per million tokens, versus $33.37 for Claude 3.7 Sonnet Pro.

Which has the larger context window?

Grok 3 Pro has the larger context window at 400,000 tokens. Claude 3.7 Sonnet Pro has 128,000 tokens.

Are these models open weights?

Claude 3.7 Sonnet Pro is proprietary; Grok 3 Pro is proprietary.

Which should I choose for production?

If you need a single default, start with Grok 3 Pro for quality-sensitive work, and check whether its price holds at your expected volume before committing.

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