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. If you want to compare the best LLMs for your data, try Agentset.
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
- 1350
Performance Record
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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
Quality Metrics
- Correctness
- 5.00
- Faithfulness
- 5.00
- Grounding
- 5.00
- Relevance
- 5.00
- Completeness
- 4.97
- Overall
- 4.99
Latency Distribution
- Mean
- 9142ms
- Min
- 4767ms
- Max
- 17055ms
MSMARCO
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
Quality Metrics
- Correctness
- 5.00
- Faithfulness
- 5.00
- Grounding
- 5.00
- Relevance
- 4.97
- Completeness
- 4.90
- Overall
- 4.97
Latency Distribution
- Mean
- 4516ms
- Min
- 2358ms
- Max
- 14942ms
Build RAG in Minutes, Not Months
Agentset gives you a complete RAG API with top-ranked LLMs and smart retrieval built in. Upload your data, call the API, and get grounded answers from day one.
import { Agentset } from "agentset";
const agentset = new Agentset();
const ns = agentset.namespace("ns_1234");
const results = await ns.search(
"What is multi-head attention?"
);
for (const result of results) {
console.log(result.text);
}Compare Models
See how it stacks up
Compare Grok 4 Fast with other top llms to understand the differences in performance, accuracy, and latency.