Grok 4.1 Fast

xAI chatvisionreasoningtool_use Long

API ID: x-ai/grok-4.1-fast

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Input Price
$0.20
/1M tokens
Output Price
$0.50
/1M tokens

About Grok 4.1 Fast

Grok 4.1 Fast is xAI's best agentic tool calling model that shines in real-world use cases like customer support and deep research. 2M context window. Reasoning can be enabled/disabled using the `reasoning` `enabled` parameter in the API. [Learn more in our docs](https://openrouter.ai/docs/use-cases/reasoning-tokens#controlling-reasoning-tokens)

💰
Price Ranking
#766 lowest price among 1240 Chat models

Model Specifications

Context Length
2.0M
Max Output
30k
Release Date
2025-11-19
Capabilities
chat vision reasoning tool_use
Input Modalities
textimage
Output Modalities
text

Best For

  • Complex reasoning, math problems, multi-step logic
  • Image analysis, document understanding, visual Q&A
  • Conversations, content writing, general assistance

Consider Alternatives For

  • Simple Q&A (cheaper models available)

💰 Real-World Cost Examples

Estimated monthly costs for common use cases

Personal AI Assistant
$0.24
/month
50 conversations/day, ~500 tokens each
Customer Service Bot
$7.50
/month
1000 tickets/day, ~800 tokens each
Data Analysis Pipeline
$10.50
/month
500 analyses/day, ~2k tokens each
Calculate Your Custom Usage

xAI Model Lineup

Compare all models from xAI to find the best fit

Model Input Output Context Capabilities
Grok 4.1 Fast Current Free Free 2.0M chat vision reasoning tool_use
Grok 2 Vision 1212 Free Free 33k chat vision
Grok 2 Vision 1212 Free Free 33k chat vision
Grok Vision Beta Free Free 8k chat vision
Grok Vision Beta Free Free 8k chat vision
Grok 2 Free Free 33k chat
View All xAI Models →

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🚀 Quick Start

Get started with Grok 4.1 Fast API

OpenAI-compatible SDK 
from openai import OpenAI

client = OpenAI(
    base_url="https://api.provider.com/v1",
    api_key="YOUR_API_KEY"
)

response = client.chat.completions.create(
    model="x-ai/grok-4.1-fast",
    messages=[
        {"role": "user", "content": "Hello!"}
    ]
)
print(response.choices[0].message.content)

Resources

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