Gemini 3 Flash vs Grok 4 Fast
Detailed comparison between Gemini 3 Flash and Grok 4 Fast for RAG applications. See which LLM best meets your accuracy, performance, and cost needs.
Model Comparison
Grok 4 Fast takes the lead.
Both Gemini 3 Flash and Grok 4 Fast are powerful language models designed for RAG applications. However, their performance characteristics differ in important ways.
Why Grok 4 Fast:
- Grok 4 Fast has 38 higher ELO rating
- Grok 4 Fast is 2.0s faster on average
Overview
Key metrics
ELO Rating
Overall ranking quality
Gemini 3 Flash
Grok 4 Fast
Win Rate
Head-to-head performance
Gemini 3 Flash
Grok 4 Fast
Quality Score
Overall quality metric
Gemini 3 Flash
Grok 4 Fast
Average Latency
Response time
Gemini 3 Flash
Grok 4 Fast
Visual Performance Analysis
Performance
ELO Rating Comparison
Win/Loss/Tie Breakdown
Quality Across Datasets (Overall Score)
Latency Distribution (ms)
Breakdown
How the models stack up
| Metric | Gemini 3 Flash | Grok 4 Fast | Description |
|---|---|---|---|
| Overall Performance | |||
| ELO Rating | 1607 | 1645 | Overall ranking quality based on pairwise comparisons |
| Win Rate | 61.0% | 58.3% | Percentage of comparisons won against other models |
| Quality Score | 4.95 | 4.96 | Average quality across all RAG metrics |
| Pricing & Context | |||
| Input Price per 1M | $0.50 | $0.20 | Cost per million input tokens |
| Output Price per 1M | $3.00 | $0.50 | Cost per million output tokens |
| Context Window | 1049K | 2000K | Maximum context window size |
| Release Date | 2025-12-17 | 2025-09-19 | Model release date |
| Performance Metrics | |||
| Avg Latency | 7.8s | 5.9s | Average response time across all datasets |
Dataset Performance
By benchmark
Comprehensive comparison of RAG quality metrics (correctness, faithfulness, grounding, relevance, completeness) and latency for each benchmark dataset.
MSMARCO
| Metric | Gemini 3 Flash | Grok 4 Fast | Description |
|---|---|---|---|
| Quality Metrics | |||
| Correctness | 4.83 | 4.90 | Factual accuracy of responses |
| Faithfulness | 4.87 | 4.90 | Adherence to source material |
| Grounding | 4.87 | 4.90 | Citations and context usage |
| Relevance | 5.00 | 5.00 | Query alignment and focus |
| Completeness | 4.90 | 4.90 | Coverage of all aspects |
| Overall | 4.89 | 4.92 | Average across all metrics |
| Latency Metrics | |||
| Mean | 6852ms | 3894ms | Average response time |
| Min | 3389ms | 1742ms | Fastest response time |
| Max | 9837ms | 6649ms | Slowest response time |
PG
| Metric | Gemini 3 Flash | Grok 4 Fast | Description |
|---|---|---|---|
| Quality Metrics | |||
| Correctness | 5.00 | 5.00 | Factual accuracy of responses |
| Faithfulness | 5.00 | 5.00 | Adherence to source material |
| Grounding | 5.00 | 5.00 | Citations and context usage |
| Relevance | 5.00 | 5.00 | Query alignment and focus |
| Completeness | 5.00 | 4.97 | Coverage of all aspects |
| Overall | 5.00 | 4.99 | Average across all metrics |
| Latency Metrics | |||
| Mean | 9444ms | 9142ms | Average response time |
| Min | 5346ms | 4767ms | Fastest response time |
| Max | 12549ms | 17055ms | Slowest response time |
SciFact
| Metric | Gemini 3 Flash | Grok 4 Fast | Description |
|---|---|---|---|
| Quality Metrics | |||
| Correctness | 5.00 | 5.00 | Factual accuracy of responses |
| Faithfulness | 5.00 | 5.00 | Adherence to source material |
| Grounding | 5.00 | 5.00 | Citations and context usage |
| Relevance | 4.97 | 5.00 | Query alignment and focus |
| Completeness | 4.83 | 4.83 | Coverage of all aspects |
| Overall | 4.96 | 4.97 | Average across all metrics |
| Latency Metrics | |||
| Mean | 7110ms | 4516ms | Average response time |
| Min | 3784ms | 2358ms | Fastest response time |
| Max | 18224ms | 14942ms | Slowest response time |
Explore More
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