Model Comparison
Gemini 3.1 Pro vs Grok 4.5Which is better in 2026?
Grok 4.5 shows notably better performance in the majority of benchmarks. Grok 4.5 is 1.9x cheaper per token.
Verdict: Gemini 3.1 Pro vs Grok 4.5 — which is better?
Gemini 3.1 Pro (by Google) and Grok 4.5 (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.
Gemini 3.1 Pro outperforms in 1 benchmarks (GPQA), while Grok 4.5 is better at 2 benchmarks (GDPval-AA, SWE-Bench Pro). Grok 4.5 shows notably better performance in the majority of benchmarks.
On price, Grok 4.5 is roughly 1.9x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.
Gemini 3.1 Pro also accepts a larger context window (1,048,576 input tokens), making it the stronger choice for long documents and large codebases.
Choose Gemini 3.1 Pro if…
- you process long inputs — it offers a 1,048,576 token context window
Choose Grok 4.5 if…
- you want the strongest raw capability — it leads on 2 of 3 shared benchmarks
- cost matters — it's about 1.9x cheaper per token
- you want the most recent training data — it shipped Jul 2026
Performance Benchmarks
Comparative analysis across standard metrics
Gemini 3.1 Pro outperforms in 1 benchmarks (GPQA), while Grok 4.5 is better at 2 benchmarks (GDPval-AA, SWE-Bench Pro).
Grok 4.5 shows notably better performance in the majority of benchmarks.
Arena Performance
Human preference votes
Pricing Analysis
Price comparison per million tokens
For input processing, Gemini 3.1 Pro ($2.50/1M tokens) is 1.3x more expensive than Grok 4.5 ($2.00/1M tokens).
For output processing, Gemini 3.1 Pro ($15.00/1M tokens) is 2.5x more expensive than Grok 4.5 ($6.00/1M tokens).
In conclusion, Gemini 3.1 Pro is more expensive than Grok 4.5.*
* Using a 3:1 ratio of input to output tokens
Context Window
Maximum input and output token capacity
Gemini 3.1 Pro accepts 1,048,576 input tokens compared to Grok 4.5's 500,000 tokens. Only Gemini 3.1 Pro specifies output context (65,536 tokens).
Input Capabilities
Supported data types and modalities
Both Gemini 3.1 Pro and Grok 4.5 support multimodal inputs.
They are both capable of processing various types of data, offering versatility in application.
Gemini 3.1 Pro
Grok 4.5
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 3.1 Pro was released on 2026-02-19, while Grok 4.5 was released on 2026-07-08.
Grok 4.5 is 5 months newer than Gemini 3.1 Pro.
Feb 19, 2026
4 months ago
Jul 8, 2026
1 weeks ago
4mo newerKnowledge Cutoff
When training data ends
Gemini 3.1 Pro has a documented knowledge cutoff of 2025-01-31, while Grok 4.5's cutoff date is not specified.
We can confirm Gemini 3.1 Pro's training data extends to 2025-01-31, but cannot make a direct comparison without Grok 4.5's cutoff date.
Jan 2025
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Provider Availability
Gemini 3.1 Pro is available from Google. Grok 4.5 is available from xAI.
Gemini 3.1 Pro
Grok 4.5
Outputs Comparison
Key Takeaways
Detailed Comparison
Interactive Arena
Judge for yourself.
Run your own prompts against Gemini 3.1 Pro and Grok 4.5 side-by-side, then vote on the output you prefer.
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FAQ
Common questions about Gemini 3.1 Pro vs Grok 4.5.