Head-to-head · frontier vs frontier

GPT-5.1 Vision vs Grok 3 Max: which model should you choose?

We compared GPT-5.1 Vision and Grok 3 Max on price, context window and 12 benchmarks. Grok 3 Max has the stronger average benchmark score; GPT-5.1 Vision is cheaper on a blended 3:1 basis.

OpenAI

GPT-5.1 Vision

GPT-5.1 Vision is a frontier model from OpenAI. It offers a 400,000-token context window, costs $17.76 per million input tokens and $80.59 per million output tokens, and averages 84.8 across the index's benchmark suite.

Input
$17.76 / 1M
Output
$80.59 / 1M
Context
400,000
Avg score
84.8
Open weights
No
Full GPT-5.1 Vision page
xAI

Grok 3 Max

Grok 3 Max is a frontier model from xAI. It offers a 2,000,000-token context window, costs $17.66 per million input tokens and $89.12 per million output tokens, and averages 85.9 across the index's benchmark suite.

Input
$17.66 / 1M
Output
$89.12 / 1M
Context
2,000,000
Avg score
85.9
Open weights
No
Full Grok 3 Max page

Specification comparison

SpecGPT-5.1 VisionGrok 3 MaxEdge
Input price / 1M$17.76$17.66B
Output price / 1M$80.59$89.12A
Context window400,0002,000,000B
Max output16,38432,768B
Average score84.885.9B
Arena Elo1462.41475.8B
Open weightsNoNoTie

Benchmark comparison

GPT-5.1 Vision wins 4, Grok 3 Max wins 7, and 1 benchmarks are tied. The table shows the modelled score for each model and the gap.

BenchmarkGPT-5.1 VisionGrok 3 MaxGapWinner
MMLU-Pro85.587.31.8Grok 3 Max
GPQA Diamond78.780.92.2Grok 3 Max
SWE-bench Verified73.673.60.0Tie
HumanEval89.691.92.3Grok 3 Max
MATH-50089.191.92.8Grok 3 Max
AIME 202582.486.64.2Grok 3 Max
LiveCodeBench77.879.71.9Grok 3 Max
IFEval92.792.60.1GPT-5.1 Vision
TruthfulQA86.986.70.2GPT-5.1 Vision
HellaSwag92.191.80.3GPT-5.1 Vision
MMMU83.982.31.6GPT-5.1 Vision
Arena Elo1462.41475.813.4Grok 3 Max

Price analysis

On a blended 3:1 input-to-output basis, GPT-5.1 Vision costs about $33.47 per million tokens and Grok 3 Max costs about $35.53. GPT-5.1 Vision is roughly 6% cheaper than Grok 3 Max. At high volume, that gap compounds quickly, so price should carry real weight unless the quality difference is decisive.

Grok 3 Max has the larger context window at 2,000,000 tokens, compared with 400,000 for GPT-5.1 Vision. That matters for long documents, large codebases and multi-step agent traces.

Verdict

Across 12 shared benchmarks, GPT-5.1 Vision wins 4, Grok 3 Max wins 7, and 1 are tied. On the index average, Grok 3 Max leads GPT-5.1 Vision by 1.1 points (85.9 versus 84.8).

The price picture favours GPT-5.1 Vision. The context picture favours Grok 3 Max. 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 Max for quality-sensitive work and GPT-5.1 Vision for high-volume, well-scoped tasks. Run both on a sample of your own traffic before locking in a choice.

Choose GPT-5.1 Vision if

  • Unit cost matters and you want the cheaper blended price.

Choose Grok 3 Max if

  • You want the higher average benchmark score in this index.
  • You need the larger 2,000,000-token context window.
  • You need the larger 32,768-token output limit.

FAQ

Is GPT-5.1 Vision better than Grok 3 Max?

On the index average, Grok 3 Max leads GPT-5.1 Vision by 1.1 points (85.9 versus 84.8). The better choice depends on price, context and your task. GPT-5.1 Vision wins 4 benchmarks, Grok 3 Max wins 7.

Which is cheaper, GPT-5.1 Vision or Grok 3 Max?

GPT-5.1 Vision is cheaper on a blended 3:1 basis at about $33.47 per million tokens, versus $35.53 for Grok 3 Max.

Which has the larger context window?

Grok 3 Max has the larger context window at 2,000,000 tokens. GPT-5.1 Vision has 400,000 tokens.

Are these models open weights?

GPT-5.1 Vision is proprietary; Grok 3 Max is proprietary.

Which should I choose for production?

If you need a single default, start with Grok 3 Max for quality-sensitive work and GPT-5.1 Vision for high-volume, well-scoped tasks. Run both on a sample of your own traffic before locking in a choice.

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