Grok 4 Fast
2M token context window enables retrieval of entire books or massive document collections without chunking. Built-in web and X search capabilities with togglable reasoning mode for flexible RAG workflows.
Model Information
- Provider
- xAI
- License
- Proprietary
- Input Price per 1M
- $0.20
- Output Price per 1M
- $0.50
- Context Window
- 2000K
- Release Date
- 2025-09-19
- Model Name
- grok-4-fast
- Total Evaluations
- 810
Performance Record
Wins487 (60.1%)
Losses210 (25.9%)
Ties113 (14.0%)
Wins
Losses
Ties
Performance Overview
ELO ratings by dataset
Grok 4 Fast's ELO performance varies across different benchmark datasets, showing its strengths in specific domains.
Grok 4 Fast - ELO by Dataset
Detailed Metrics
Dataset breakdown
Performance metrics across different benchmark datasets, including accuracy and latency percentiles.
PG
ELO 183676.7% WR207W-50L-13T
Quality Metrics
- Correctness
- 5.00
- Faithfulness
- 5.00
- Grounding
- 5.00
- Relevance
- 5.00
- Completeness
- 4.93
- Overall
- 4.99
Latency Distribution
- Mean
- 9142ms
- Min
- 4767ms
- Max
- 17055ms
MSMARCO
ELO 158561.1% WR165W-70L-35T
Quality Metrics
- Correctness
- 4.90
- Faithfulness
- 4.90
- Grounding
- 4.90
- Relevance
- 5.00
- Completeness
- 4.83
- Overall
- 4.91
Latency Distribution
- Mean
- 3894ms
- Min
- 1742ms
- Max
- 6649ms
SciFact
ELO 154742.6% WR115W-90L-65T
Quality Metrics
- Correctness
- 5.00
- Faithfulness
- 5.00
- Grounding
- 5.00
- Relevance
- 5.00
- Completeness
- 4.83
- Overall
- 4.97
Latency Distribution
- Mean
- 4516ms
- Min
- 2358ms
- Max
- 14942ms
Compare Models
See how it stacks up
Compare Grok 4 Fast with other top llms to understand the differences in performance, accuracy, and latency.