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GPT-4.1 mini vs Grok 4 Fast

Grok 4 Fast leads the LLM Stats Score 31.7 to 14.0. Grok 4 Fast is 2.5x cheaper per token.

OpenAI · xAI · Updated for 2026

Which is better?

Grok 4 Fast leads the overall LLM Stats Score 31.7 to 14.0, ranking #110 overall.

In the 4 individual benchmarks reported for both models, Grok 4 Fast wins 4; this is a narrower head-to-head signal than the composite indexes.

On price, Grok 4 Fast is roughly 2.5x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.

Grok 4 Fast also accepts a larger context window (2,000,000 input tokens), making it the stronger choice for long documents and large codebases.

Based on current LLM Stats indexes, shared benchmarks, pricing, and model metadata for 2026.

Choose GPT-4.1 mini

  • you want predictable pricing at $0.40/M input and $1.60/M output

Choose Grok 4 Fast

  • overall performance matters — it scores 31.7 and ranks #110 on LLM Stats
  • your work emphasizes reasoning and coding — it leads those capability indexes
  • you value its reported benchmark strengths — it wins 4 of 4 exact shared results
  • cost matters — it's about 2.5x cheaper per token
  • you process long inputs — it offers a 2,000,000 token context window
  • you want the most recent training data — it shipped Aug 2025

At a glance

The differences that matter most.

Core performance indexes
14.0
#239
31.7
#110
13.9
#232
30.7
#115
-3.3
#253
18.1
#112
Cost, coverage & limits
Benchmark wins
0 of 4
4 of 4
Input price
$0.40 / M
$0.20 / M
Output price
$1.60 / M
$0.50 / M
Context window
1,047,576
2,000,000

Capability indexes

Additional strengths measured across groups of related public benchmarks

1 shared
Index
GPT-4.1 mini
Grok 4 Fast
13.6#225
27.3#99
Conservative TrueSkill rating · higher is betterHow scores work

Individual benchmarks

28 reported for GPT-4.1 mini · 7 for Grok 4 Fast

4 shared

GPT-4.1 mini outperforms in 0 benchmarks, while Grok 4 Fast is better at 4 benchmarks (AIME 2025, GPQA, HMMT 2025, Humanity's Last Exam).

Grok 4 Fast significantly outperforms across most benchmarks.

Mon Sep 21 2026 • llm-stats.com

Human preference

Blind head-to-head votes and playground preference scores

Pricing Analysis

Price comparison per million tokens

Grok 4 Fast costs less

For input processing, GPT-4.1 mini ($0.40/1M tokens) is 2.0x more expensive than Grok 4 Fast ($0.20/1M tokens).

For output processing, GPT-4.1 mini ($1.60/1M tokens) is 3.2x more expensive than Grok 4 Fast ($0.50/1M tokens).

In conclusion, GPT-4.1 mini is more expensive than Grok 4 Fast.*

* Using a 3:1 ratio of input to output tokens

Lowest available price from all providers
Mon Sep 21 2026 • llm-stats.com
OpenAI
GPT-4.1 mini
Input tokens$0.40
Output tokens$1.60
Best providerOpenAI
xAI
Grok 4 Fast
Input tokens$0.20
Output tokens$0.50
Best providerxAI
Notice missing or incorrect data?Start an Issue

Context Window

Maximum input and output token capacity

Grok 4 Fast accepts 2,000,000 input tokens compared to GPT-4.1 mini's 1,047,576 tokens. GPT-4.1 mini can generate longer responses up to 32,768 tokens, while Grok 4 Fast is limited to 30,000 tokens.

OpenAI
GPT-4.1 mini
Input1,047,576 tokens
Output32,768 tokens
xAI
Grok 4 Fast
Input2,000,000 tokens
Output30,000 tokens
Mon Sep 21 2026 • llm-stats.com

Input capabilities

Documented input modalities across available providers

Both GPT-4.1 mini and Grok 4 Fast support multimodal inputs.

They are both capable of processing various types of data, offering versatility in application.

GPT-4.1 mini

Text
Images
Audio
Video

Grok 4 Fast

Text
Images
Audio
Video

License

Usage and distribution terms

Both models are licensed under proprietary licenses.

Both models have usage restrictions defined by their respective organizations.

GPT-4.1 mini

Proprietary

Closed source

Grok 4 Fast

Proprietary

Closed source

Release Timeline

When each model was launched

GPT-4.1 mini was released on 2025-04-14, while Grok 4 Fast was released on 2025-08-28.

Grok 4 Fast is 5 months newer than GPT-4.1 mini.

GPT-4.1 mini

Apr 14, 2025

1.4 years ago

Grok 4 Fast

Aug 28, 2025

1.1 years ago

4mo newer

Knowledge Cutoff

When training data ends

GPT-4.1 mini has a documented knowledge cutoff of 2024-05-31, while Grok 4 Fast's cutoff date is not specified.

We can confirm GPT-4.1 mini's training data extends to 2024-05-31, but cannot make a direct comparison without Grok 4 Fast's cutoff date.

GPT-4.1 mini

May 2024

Grok 4 Fast

Provider Availability

GPT-4.1 mini is available from OpenAI. Grok 4 Fast is available from xAI.

GPT-4.1 mini

openai logo
OpenAI
Input Price:Input: $0.40/1MOutput Price:Output: $1.60/1M

Grok 4 Fast

xai logo
xAI
Input Price:Input: $0.20/1MOutput Price:Output: $0.50/1M
* Prices shown are per million tokens

Outputs Comparison

Notice missing or incorrect data?Start an Issue discussion

Judge for yourself.

Run your own prompts against GPT-4.1 mini and Grok 4 Fast side-by-side, then vote on the output you prefer.

GPT-4.1 mini
✓ Preferred
Grok 4 Fast
Open in Playground

FAQ

Common questions about GPT-4.1 mini vs Grok 4 Fast.

Which is better, GPT-4.1 mini or Grok 4 Fast?

Grok 4 Fast leads the LLM Stats Score 31.7 to 14.0. GPT-4.1 mini is made by OpenAI and Grok 4 Fast is made by xAI. The best choice depends on your use case — compare their capability indexes, individual benchmarks, pricing, and limits above.

How does GPT-4.1 mini compare to Grok 4 Fast in benchmarks?

GPT-4.1 mini scores CharXiv-D: 88.4%, MMLU: 87.5%, IFEval: 84.1%, MMMLU: 78.5%, MathVista: 73.1%. Grok 4 Fast scores SimpleQA: 95.0%, HMMT 2025: 93.3%, AIME 2025: 92.0%, GPQA: 85.7%, LiveCodeBench: 80.0%.

Is GPT-4.1 mini cheaper than Grok 4 Fast?

Grok 4 Fast is 2.0x cheaper for input tokens. GPT-4.1 mini costs $0.40/M input and $1.60/M output via openai. Grok 4 Fast costs $0.20/M input and $0.50/M output via xai.

What are the context window sizes for GPT-4.1 mini and Grok 4 Fast?

GPT-4.1 mini supports 1.0M tokens and Grok 4 Fast supports 2.0M tokens. A larger context window lets you process longer documents, conversations, or codebases in a single request.

What are the main differences between GPT-4.1 mini and Grok 4 Fast?

Key differences include LLM Stats Score (14.0 vs 31.7), context window (1.0M vs 2.0M), input pricing ($0.40 vs $0.20/M). See the full comparison above for benchmark-by-benchmark results.

Who makes GPT-4.1 mini and Grok 4 Fast?

GPT-4.1 mini is developed by OpenAI and Grok 4 Fast is developed by xAI.