Model Comparison
Gemini 2.5 Pro Preview 06-05 vs Grok-4.1 Fast ReasoningWhich is better in 2026?
Comparing Gemini 2.5 Pro Preview 06-05 and Grok-4.1 Fast Reasoning across benchmarks, pricing, and capabilities.
Verdict: Gemini 2.5 Pro Preview 06-05 vs Grok-4.1 Fast Reasoning — which is better?
Gemini 2.5 Pro Preview 06-05 (by Google) and Grok-4.1 Fast Reasoning (by xAI) are two of the AI models people compare most. Here is how they stack up on benchmarks, price and capabilities, and which one to pick in 2026.
On price, Grok-4.1 Fast Reasoning is roughly 12.5x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.
Grok-4.1 Fast Reasoning also accepts a larger context window (2,000,000 input tokens), making it the stronger choice for long documents and large codebases.
Choose Gemini 2.5 Pro Preview 06-05 if…
- you want predictable pricing at $1.25/M input and $10.00/M output
Choose Grok-4.1 Fast Reasoning if…
- 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 Nov 2025
Performance Benchmarks
Comparative analysis across standard metrics
Gemini 2.5 Pro Preview 06-05 and Grok-4.1 Fast Reasoningdon't have any common benchmark datasets to compare. They may have been evaluated on different testing suites.
Arena Performance
Human preference votes
Pricing Analysis
Price comparison per million tokens
For input processing, Gemini 2.5 Pro Preview 06-05 ($1.25/1M tokens) is 6.3x more expensive than Grok-4.1 Fast Reasoning ($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-4.1 Fast Reasoning ($0.50/1M tokens).
In conclusion, Gemini 2.5 Pro Preview 06-05 is more expensive than Grok-4.1 Fast Reasoning.*
* Using a 3:1 ratio of input to output tokens
Context Window
Maximum input and output token capacity
Grok-4.1 Fast Reasoning 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-4.1 Fast Reasoning is limited to 30,000 tokens.
Input Capabilities
Supported data types and modalities
Both Gemini 2.5 Pro Preview 06-05 and Grok-4.1 Fast Reasoning support multimodal inputs.
They are both capable of processing various types of data, offering versatility in application.
Gemini 2.5 Pro Preview 06-05
Grok-4.1 Fast Reasoning
License
Usage and distribution terms
Both models are licensed under proprietary licenses.
Both models have usage restrictions defined by their respective organizations.
Proprietary
Closed source
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-4.1 Fast Reasoning was released on 2025-11-17.
Grok-4.1 Fast Reasoning is 6 months newer than Gemini 2.5 Pro Preview 06-05.
Jun 5, 2025
1.0 years ago
Nov 17, 2025
6 months ago
5mo newerKnowledge Cutoff
When training data ends
Gemini 2.5 Pro Preview 06-05 has a documented knowledge cutoff of 2025-01-31, while Grok-4.1 Fast Reasoning'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-4.1 Fast Reasoning's cutoff date.
Jan 2025
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Provider Availability
Gemini 2.5 Pro Preview 06-05 is available from Google. Grok-4.1 Fast Reasoning is available from xAI.
Gemini 2.5 Pro Preview 06-05
Grok-4.1 Fast Reasoning
Outputs Comparison
Key Takeaways
No standout differentiators in the data we have for this pair.
Detailed Comparison
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FAQ
Common questions about Gemini 2.5 Pro Preview 06-05 vs Grok-4.1 Fast Reasoning.