Grok 4.1 Fast (Reasoning) vs GPT-5.1 Codex mini (high): The Ultimate Performance & Pricing Comparison

Deep dive into reasoning, benchmarks, and latency insights.

The Final Verdict in the Grok 4.1 Fast (Reasoning) vs GPT-5.1 Codex mini (high) Showdown

After a comprehensive analysis, GPT-5.1 Codex mini (high) emerges as the superior choice for users prioritizing raw intelligence and reasoning. However, Grok 4.1 Fast (Reasoning) remains a highly competitive option, especially for scenarios demanding faster response times and cost-efficiency. This detailed Grok 4.1 Fast (Reasoning) vs GPT-5.1 Codex mini (high) comparison will break down every critical metric to help you make the best decision.

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Model Snapshot

Key decision metrics at a glance.

Grok 4.1 Fast (Reasoning)

xAI

Reasoning: 9
Coding: 3
Multimodal: 3
Long Context: 5
Blended Price / 1M tokens: $0.000
P95 Latency: 1000ms
Tokens per second: 182.829tokens/sec

GPT-5.1 Codex mini (high)

OpenAI

Reasoning: 9
Coding: 4
Multimodal: 3
Long Context: 5
Blended Price / 1M tokens: $0.001
P95 Latency: 1000ms
Tokens per second: 85.505tokens/sec

Overall Capabilities

The capability radar provides a holistic view of the Grok 4.1 Fast (Reasoning) vs GPT-5.1 Codex mini (high) matchup. This chart illustrates each model's strengths and weaknesses at a glance, forming a cornerstone of our Grok 4.1 Fast (Reasoning) vs GPT-5.1 Codex mini (high) analysis.

This radar chart visually maps the core capabilities (reasoning, coding, math proxy, multimodal, long context) of `Grok 4.1 Fast (Reasoning)` vs `GPT-5.1 Codex mini (high)`.

Benchmark Breakdown

For a granular look, this chart directly compares scores across standardized benchmarks. In the critical MMLU Pro test, a key part of the Grok 4.1 Fast (Reasoning) vs GPT-5.1 Codex mini (high) debate, Grok 4.1 Fast (Reasoning) scores 90 against GPT-5.1 Codex mini (high)'s 90. This data-driven approach is essential for any serious Grok 4.1 Fast (Reasoning) vs GPT-5.1 Codex mini (high) comparison.

This grouped bar chart provides a side-by-side comparison for each benchmark metric.

Speed & Latency

Speed is a crucial factor in the Grok 4.1 Fast (Reasoning) vs GPT-5.1 Codex mini (high) decision for interactive applications. The metrics below highlight the trade-offs you should weigh before shipping to production.

Time to First Token

Grok 4.1 Fast (Reasoning)300ms

GPT-5.1 Codex mini (high)300ms

Tokens per Second

Grok 4.1 Fast (Reasoning)182.829

GPT-5.1 Codex mini (high)85.505

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The Economics of Grok 4.1 Fast (Reasoning) vs GPT-5.1 Codex mini (high)

Power is only one part of the equation. This Grok 4.1 Fast (Reasoning) vs GPT-5.1 Codex mini (high) pricing analysis gives you a true sense of value.

Pricing Breakdown

Compare input and output pricing at a glance.

Real-World Cost Scenario

To process 1M input tokens and generate 250k output tokens, Grok 4.1 Fast (Reasoning) would cost $0.000, whereas GPT-5.1 Codex mini (high) would cost $0.001. This practical calculation is vital for any developer considering the Grok 4.1 Fast (Reasoning) vs GPT-5.1 Codex mini (high) choice.

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Which Model Wins the Grok 4.1 Fast (Reasoning) vs GPT-5.1 Codex mini (high) Battle for You?

Choose Grok 4.1 Fast (Reasoning) if...

Your top priority is raw performance and capability.

You need the most advanced reasoning capabilities available.

Your use case demands cutting-edge AI performance.

Choose GPT-5.1 Codex mini (high) if...

You are developing at scale where operational costs are critical.

You prioritize cost-effectiveness over maximum performance.

Your workload requires consistent, reliable performance.

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Your Questions about the Grok 4.1 Fast (Reasoning) vs GPT-5.1 Codex mini (high) Comparison

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Data source: https://artificialanalysis.ai/