Model Comparison
Grok 4 Fast (Non-reasoning)
vs. Gemini 3.1 Pro Preview
Comparing 2 AI models · 10 benchmarks · xAI, Google
Recommended Pick
Go Gemini 3.1 Pro Preview 11 metric wins Strongest on: Throughput, Reasoning, Intelligence
Best Value
Grok 4 Fast (Non-reasoning)
100.0 value score
34.3 reasoning / $0.28/1M
Lowest Price
Grok 4 Fast (Non-reasoning)
$0.20/1M input price
Best Reasoning
Gemini 3.1 Pro Preview
65.3 reasoning score
Blends available reasoning benchmarks
Best for Coding
Gemini 3.1 Pro Preview
55.5 coding index
Composite Indices
Higher is better; speed and price are normalized
Standard Benchmarks
Only benchmarks with data are shown
Differences That Matter
Best value
Grok 4 Fast (Non-reasoning) has the strongest quality-to-price mix at 100.0 out of 100 value points.
Price gap
Grok 4 Fast (Non-reasoning) is 10x cheaper on input tokens than Gemini 3.1 Pro Preview.
Reasoning gap
Gemini 3.1 Pro Preview leads Grok 4 Fast (Non-reasoning) by 31.1 points on reasoning.
Coding gap
Gemini 3.1 Pro Preview leads Grok 4 Fast (Non-reasoning) by 36.5 points on coding.
Top-pick rationale
Gemini 3.1 Pro Preview wins 11 measurable categories, including Throughput, Reasoning, Intelligence, Coding.
Response Face-Off
Run one prompt through the selected models and compare response quality with live speed and cost context.
Grok 4 Fast (Non-reasoning)
xAI
TTFT
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Time
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tok/s
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Tokens
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Cost
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Gemini 3.1 Pro Preview
TTFT
—
Time
—
tok/s
—
Tokens
—
Cost
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Which answer was more useful?
Full Comparison
| Metric | xA Grok 4 Fast (Non-reasoning) | Top Pick Go Gemini 3.1 Pro Preview |
|---|---|---|
| Pricing per 1M tokens | ||
| Input Cost | $0.20/1M | $2.00/1M |
| Output Cost | $0.50/1M | $12.00/1M |
| Blended (3:1) | $0.28/1M | $4.50/1M |
| Specifications | ||
| Organization | xAI | |
| Release Date | Sep 19, 2025 | Feb 19, 2026 |
| Performance & Speed | ||
| Throughput | — | 116.3 tok/s |
| TTFT | — | 20054ms |
| Latency | — | 20054ms |
| Composite Indices | ||
| Value Score | 100.0 | 11.7 |
| Reasoning Score | 34.3 | 65.3 |
| Intelligence | 23.1 | 57.2 |
| Coding | 19.0 | 55.5 |
| Math | 41.3 | — |
| Standard Benchmarks | ||
| GPQA | 60.6% | 94.1% |
| MMLU Pro | 73.0% | — |
| HLE | 5.0% | 44.7% |
| LiveCodeBench | 40.1% | — |
| AIME 2025 | 41.3% | — |
| SciCode | 32.9% | 58.9% |
| LCR | 20.0% | 72.7% |
| IFBench | 37.7% | 77.1% |
| TAU-bench v2 | 63.7% | 95.6% |
| TerminalBench Hard | 12.1% | 53.8% |
Key Takeaways
Grok 4 Fast (Non-reasoning) offers the best value at $0.20/1M, making it ideal for high-volume applications and cost-conscious projects.
Gemini 3.1 Pro Preview has the strongest reasoning profile with a 65.3 reasoning score, combining the available reasoning-heavy benchmarks.
Gemini 3.1 Pro Preview reaches a 55.5 coding index, making it the top choice for software development and code generation tasks.
All models support context windows of ∞+ tokens, suitable for processing lengthy documents and maintaining extended conversations.
When to Choose Each Model
Grok 4 Fast (Non-reasoning)
- Cost-sensitive applications
- High-volume processing
Gemini 3.1 Pro Preview
- Complex reasoning tasks
- Research & analysis
- Code generation
- Software development
