Grok 4.1 Fast
xAI
Best tool-calling model with 2M context window. Optimized for speed, accuracy, and enterprise agentic workflows. Trained with long-horizon RL for consistent performance across full context. Available as grok-4-1-fast-reasoning and grok-4-1-fast-non-reasoning variants.
Text Generation API Grok Family
Parameters
-
params
Context Window
2.0M
tokens
Max Output
-
tokens
Input Price
$0.2
per 1M tokens
Output Price
$0.5
per 1M tokens
Grok Family 9 models
The full Grok line by generation — pricing and capabilities vary across the family.
Grok
4.1 Fast Current
$0.2 / $0.5
in / out · 1M
4.1
$3 / $15
in / out · 1M
Code Fast 1
$0.2 / $1.5
in / out · 1M
4
$3 / $15
in / out · 1M
2
Real-time knowledge, wit
$5 / $10
in / out · 1M
Capabilities
👁️
Vision
⚡
Function Calling
📋
JSON Mode
🌊
Streaming
💬
System Prompt
🖥️
Code Execution
🔍
Web Search
🔌
MCP Support
Extended Pricing
Input
$0.2/1M
Output
$0.5/1M
Cache Read
$0.75/1M
Details
- Release Date
- November 19, 2025
- Knowledge Cutoff
- November 1, 2024
- Source
- API
- API Key Required
- Yes
- License
- Proprietary
- Model ID
- grok-4.1-fast
Last updated: March 13, 2026