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Gemini 2.5 Pro Preview 06-05 vs Grok 4 Fast

Gemini 2.5 Pro Preview 06-05 and Grok 4 Fast are closely matched at 29.9 and 32.0 on the LLM Stats Score. Grok 4 Fast is 12.5x cheaper per token.

Google · xAI · Updated for 2026

Which is better?

Gemini 2.5 Pro Preview 06-05 and Grok 4 Fast are closely matched on the overall LLM Stats Score at 29.9 and 32.0.

In the 5 individual benchmarks reported for both models, Grok 4 Fast wins 3; this is a narrower head-to-head signal than the composite indexes.

On price, Grok 4 Fast is roughly 12.5x 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 Gemini 2.5 Pro Preview 06-05

  • you want predictable pricing at $1.25/M input and $10.00/M output

Choose Grok 4 Fast

  • you value its reported benchmark strengths — it wins 3 of 5 exact shared results
  • cost matters — it's about 12.5x 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
29.9
#116
32.0
#101
28.3
#120
31.1
#103
17.0
#117
18.3
#106
Cost, coverage & limits
Benchmark wins
2 of 5
3 of 5
Input price
$1.25 / M
$0.20 / M
Output price
$10.00 / M
$0.50 / M
Context window
1,048,576
2,000,000

Capability indexes

Additional strengths measured across groups of related public benchmarks

1 shared
Index
Gemini 2.5 Pro Preview 06-05
Grok 4 Fast
22.2#134
27.4#94
Conservative TrueSkill rating · higher is betterHow scores work

Individual benchmarks

13 reported for Gemini 2.5 Pro Preview 06-05 · 7 for Grok 4 Fast

5 shared

Gemini 2.5 Pro Preview 06-05 outperforms in 2 benchmarks (GPQA, Humanity's Last Exam), while Grok 4 Fast is better at 3 benchmarks (AIME 2025, LiveCodeBench, SimpleQA).

Grok 4 Fast has a slight edge in benchmark performance.

Sat Sep 05 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, Gemini 2.5 Pro Preview 06-05 ($1.25/1M tokens) is 6.3x more expensive than Grok 4 Fast ($0.20/1M tokens).

For output processing, Gemini 2.5 Pro Preview 06-05 ($10.00/1M tokens) is 20.0x more expensive than Grok 4 Fast ($0.50/1M tokens).

In conclusion, Gemini 2.5 Pro Preview 06-05 is more expensive than Grok 4 Fast.*

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

Lowest available price from all providers
Sat Sep 05 2026 • llm-stats.com
Google
Gemini 2.5 Pro Preview 06-05
Input tokens$1.25
Output tokens$10.00
Best providerGoogle
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 Gemini 2.5 Pro Preview 06-05's 1,048,576 tokens. Gemini 2.5 Pro Preview 06-05 can generate longer responses up to 65,535 tokens, while Grok 4 Fast is limited to 30,000 tokens.

Google
Gemini 2.5 Pro Preview 06-05
Input1,048,576 tokens
Output65,535 tokens
xAI
Grok 4 Fast
Input2,000,000 tokens
Output30,000 tokens
Sat Sep 05 2026 • llm-stats.com

Input capabilities

Documented input modalities across available providers

Both Gemini 2.5 Pro Preview 06-05 and Grok 4 Fast support multimodal inputs.

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

Gemini 2.5 Pro Preview 06-05

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.

Gemini 2.5 Pro Preview 06-05

Proprietary

Closed source

Grok 4 Fast

Proprietary

Closed source

Release Timeline

When each model was launched

Gemini 2.5 Pro Preview 06-05 was released on 2025-06-05, while Grok 4 Fast was released on 2025-08-28.

Grok 4 Fast is 3 months newer than Gemini 2.5 Pro Preview 06-05.

Gemini 2.5 Pro Preview 06-05

Jun 5, 2025

1.3 years ago

Grok 4 Fast

Aug 28, 2025

1.0 years ago

2mo newer

Knowledge Cutoff

When training data ends

Gemini 2.5 Pro Preview 06-05 has a documented knowledge cutoff of 2025-01-31, while Grok 4 Fast's cutoff date is not specified.

We can confirm Gemini 2.5 Pro Preview 06-05's training data extends to 2025-01-31, but cannot make a direct comparison without Grok 4 Fast's cutoff date.

Gemini 2.5 Pro Preview 06-05

Jan 2025

Grok 4 Fast

Provider Availability

Gemini 2.5 Pro Preview 06-05 is available from Google. Grok 4 Fast is available from xAI.

Gemini 2.5 Pro Preview 06-05

google logo
Google
Input Price:Input: $1.25/1MOutput Price:Output: $10.00/1M

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 Gemini 2.5 Pro Preview 06-05 and Grok 4 Fast side-by-side, then vote on the output you prefer.

Gemini 2.5 Pro Preview 06-05
✓ Preferred
Grok 4 Fast
Open in Playground

FAQ

Common questions about Gemini 2.5 Pro Preview 06-05 vs Grok 4 Fast.

Which is better, Gemini 2.5 Pro Preview 06-05 or Grok 4 Fast?

Gemini 2.5 Pro Preview 06-05 and Grok 4 Fast are closely matched on the LLM Stats Score at 29.9 and 32.0. Gemini 2.5 Pro Preview 06-05 is made by Google 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 Gemini 2.5 Pro Preview 06-05 compare to Grok 4 Fast in benchmarks?

Gemini 2.5 Pro Preview 06-05 scores Global-MMLU-Lite: 89.2%, AIME 2025: 88.0%, FACTS Grounding: 87.8%, GPQA: 86.4%, VideoMMMU: 83.6%. Grok 4 Fast scores SimpleQA: 95.0%, HMMT 2025: 93.3%, AIME 2025: 92.0%, GPQA: 85.7%, LiveCodeBench: 80.0%.

Is Gemini 2.5 Pro Preview 06-05 cheaper than Grok 4 Fast?

Grok 4 Fast is 6.3x cheaper for input tokens. Gemini 2.5 Pro Preview 06-05 costs $1.25/M input and $10.00/M output via google. Grok 4 Fast costs $0.20/M input and $0.50/M output via xai.

What are the context window sizes for Gemini 2.5 Pro Preview 06-05 and Grok 4 Fast?

Gemini 2.5 Pro Preview 06-05 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 Gemini 2.5 Pro Preview 06-05 and Grok 4 Fast?

Key differences include LLM Stats Score (29.9 vs 32.0), context window (1.0M vs 2.0M), input pricing ($1.25 vs $0.20/M). See the full comparison above for benchmark-by-benchmark results.

Who makes Gemini 2.5 Pro Preview 06-05 and Grok 4 Fast?

Gemini 2.5 Pro Preview 06-05 is developed by Google and Grok 4 Fast is developed by xAI.