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Google: Gemini 3.1 Pro Preview vs xAI: Grok 4: Coding Performance with 10 Evaluators

We put Google: Gemini 3.1 Pro Preview and xAI: Grok 4 to the test in a rigorous Coding Performance evaluation assessed by 10 specialized evaluators.

Google: Gemini 3.1 Pro Preview

7.0

preference score

vs

xAI: Grok 4

3.0

preference score

Judges ranked the responses in this Run against each other; the rank is mapped onto a 0–10 scale. It shows which response was preferred, not how good either one is — and it is not a percentage, a pass rate, or a check that the output was correct.

Sample size for this comparison was not recorded. Treat it as directional.

Evidence clarification: this article predates recorded sample provenance. Treat its conclusions as claims about the displayed examples; they do not establish general model superiority, verified correctness, or production suitability.

Key Findings

Coding AccuracyGoogle: Gemini 3.1 Pro Preview

Gemini secured a 7.03 score, significantly outpacing Grok 4's 2.97 in technical precision.

Instruction AdherenceGoogle: Gemini 3.1 Pro Preview

Gemini 3.1 Pro followed complex coding constraints with higher reliability across all evaluator segments.

Cost EfficiencyGoogle: Gemini 3.1 Pro Preview

Despite longer responses, Gemini proved more cost-effective per request than Grok 4.

Specifications

SpecGoogle: Gemini 3.1 Pro PreviewxAI: Grok 4
Providergooglex-ai
Context Length1.0M256K
Input Price (per 1M tokens)$2.00$3.00
Output Price (per 1M tokens)$12.00$15.00
Tierpremiumfrontier

Our Verdict

Google: Gemini 3.1 Pro Preview is the clear winner for coding-intensive applications, providing superior accuracy and instruction following at a lower cost. xAI: Grok 4 struggled to compete in this specific benchmark, suggesting it may not be the optimal choice for precision-heavy software development tasks at this time.

Overview

In the rapidly evolving landscape of Large Language Models, choosing the right tool for software engineering tasks is critical. This PeerLM analysis focuses on a head-to-head comparison between Google: Gemini 3.1 Pro Preview and xAI: Grok 4. By utilizing a specialized suite focused on Coding Performance with 10 Evaluators, we provide an objective look at how these models handle complex programming instructions and technical accuracy.

Benchmark Results

The evaluation was conducted using a comparative ranking methodology, where 10 expert evaluators assessed the output quality of each model based on real-world coding challenges.

ModelOverall ScoreAccuracyInstruction Following
Google: Gemini 3.1 Pro Preview7.037.037.03
xAI: Grok 42.972.972.97

Criteria Breakdown

Our assessment focused on two primary pillars of coding competency: Accuracy and Instruction Following. The data highlights a distinct performance gap in this specific coding suite.

  • Accuracy: Gemini 3.1 Pro Preview demonstrated a statistically significant lead, consistently producing syntactically correct and logically sound code snippets. Grok 4 struggled to maintain the same level of precision across the 10-evaluator test set.
  • Instruction Following: When provided with complex constraints—such as specific library requirements or architectural patterns—Gemini 3.1 Pro Preview adhered more strictly to the prompt requirements, whereas Grok 4 exhibited a higher rate of drift from the original instructions.

Cost & Latency

Understanding the economic footprint of your LLM integration is as important as the performance itself. Below is a breakdown of the costs associated with the evaluation run.

ModelTotal Cost (USD)Avg Prompt TokensAvg Completion Tokens
Google: Gemini 3.1 Pro Preview$0.07912181612
xAI: Grok 4$0.09258951363

Interestingly, despite Gemini 3.1 Pro Preview producing a higher volume of completion tokens, it maintained a lower total cost profile compared to Grok 4, making it a more efficient choice for high-throughput coding tasks.

Use Cases

Based on the Coding Performance with 10 Evaluators results, the following use cases are recommended:

  • Google: Gemini 3.1 Pro Preview: Best suited for complex refactoring, writing boilerplate code, and debugging tasks where logical accuracy and constraint satisfaction are paramount.
  • xAI: Grok 4: While trailing in this specific coding bench, Grok 4 may still find utility in creative brainstorming or general conversational tasks where the rigid constraints of code generation are not the primary focus.

Verdict

The comparative analysis clearly favors Google's latest offering in a programming context. By outperforming the competition in both accuracy and adherence to specific coding constraints, Gemini 3.1 Pro Preview establishes itself as the more reliable engine for developer-centric workflows.

Backed by real data

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See every response, score, and evaluator judgment behind this comparison. All data from PeerLM's blind evaluation pipeline.

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Methodology

Evaluated using PeerLM's blind evaluation pipeline with 4 responses per model across 2 criteria.