xAI: Grok 4 Fast Non-Reasoning

Access Grok 4 Fast Non-Reasoning from xAI using Puter.js AI API.

Get Started

Model Card

Grok 4 Fast Non-Reasoning is the speed-optimized, non-reasoning variant of Grok 4 Fast that bypasses extended chain-of-thought for instant responses. It uses the same unified architecture with a 2M context window but skips deliberation, delivering up to 342 tokens/second throughput for high-volume, latency-sensitive applications.

Context Window N/A

tokens

Max Output 2M

tokens

Input Cost $0.2

per million tokens

Output Cost $0.5

per million tokens

Input text, image

modalities

Tool Use Yes

 

Knowledge Cutoff Jul 2025

 

Release Date Sep 19, 2025

 

API Usage Example

Add Grok 4 Fast Non-Reasoning to your app with just a few lines of code.
No backend, no configuration required.

// npm install @heyputer/puter.js
import { puter } from '@heyputer/puter.js';

puter.ai.chat("Explain quantum computing in simple terms", {
    model: "x-ai/grok-4-fast-non-reasoning"
}).then(response => {
    document.body.innerHTML = response.message.content;
});

<html>
<body>
    <script src="https://js.puter.com/v2/"></script>
    <script>
        puter.ai.chat("Explain quantum computing in simple terms", {
            model: "x-ai/grok-4-fast-non-reasoning"
        }).then(response => {
            document.body.innerHTML = response.message.content;
        });
    </script>
</body>
</html>

# pip install openai
from openai import OpenAI

client = OpenAI(
    base_url="https://api.puter.com/puterai/openai/v1/",
    api_key="YOUR_PUTER_AUTH_TOKEN",
)

response = client.chat.completions.create(
    model="x-ai/grok-4-fast-non-reasoning",
    messages=[
        {"role": "user", "content": "Explain quantum computing in simple terms"}
    ],
)

print(response.choices[0].message.content)

curl https://api.puter.com/puterai/openai/v1/chat/completions \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer YOUR_PUTER_AUTH_TOKEN" \
  -d '{
    "model": "x-ai/grok-4-fast-non-reasoning",
    "messages": [
      {"role": "user", "content": "Explain quantum computing in simple terms"}
    ]
  }'

View full documentation →

More AI Models From xAI

Chat

Grok 4.20 Beta

Grok 4.20 Beta is xAI's newest flagship model, featuring a native 4-agent collaboration system (Grok, Harper, Benjamin, Lucas) that reasons in parallel and debates internally before delivering a unified response. It introduces a rapid-learning architecture that improves weekly from real-world feedback, and builds on a ~3T parameter MoE backbone with up to 2M token context. It claims a 65% reduction in hallucinations over Grok 4.1 and strong gains in coding, math, and engineering reasoning.

 Chat

Grok 4.20 Multi-Agent Beta

Grok 4.20 Multi-Agent Beta is an API-specific variant of Grok 4.20 optimized for orchestrating multiple agents that collaborate on deep research tasks. It supports web search and X search tools natively, uses the same 2M token context window, and is designed for developer workflows requiring structured multi-agent collaboration.

 Chat

Grok 4.1 Fast

Grok 4.1 Fast is xAI's best tool-calling model released November 2025, featuring a 2M context window and halved hallucination rates versus Grok 4 Fast. It comes in reasoning and non-reasoning modes and is optimized for agentic workflows with native support for web search, X search, and code execution.

View all xAI models →

Frequently Asked Questions

How do I use Grok 4 Fast Non-Reasoning?

You can access Grok 4 Fast Non-Reasoning by xAI through Puter.js AI API. Include the library in your web app or Node.js project and start making calls with just a few lines of JavaScript — no backend and no configuration required. You can also use it with Python or cURL via Puter's OpenAI-compatible API.

Is Grok 4 Fast Non-Reasoning free?

Yes, it is free if you're using it through Puter.js. With the User-Pays Model, you can add Grok 4 Fast Non-Reasoning to your app at no cost — your users pay for their own AI usage directly, making it completely free for you as a developer.

What is the pricing for Grok 4 Fast Non-Reasoning?
Pricing for Grok 4 Fast Non-Reasoning is based on the number of input and output tokens used per request.
Price per 1M tokens
Input$0.2
Output$0.5
Who created Grok 4 Fast Non-Reasoning?

Grok 4 Fast Non-Reasoning was created by xAI and released on Sep 19, 2025.

What is the max output length of Grok 4 Fast Non-Reasoning?

Grok 4 Fast Non-Reasoning can generate up to 2M tokens in a single response.

What is the knowledge cutoff of Grok 4 Fast Non-Reasoning?

Grok 4 Fast Non-Reasoning has a knowledge cutoff date of Jul 2025. This means the model was trained on data available up to that date.

What types of input can Grok 4 Fast Non-Reasoning process?

Grok 4 Fast Non-Reasoning accepts the following input types: text, image. It produces: text.

Does Grok 4 Fast Non-Reasoning support tool use (function calling)?

Yes, Grok 4 Fast Non-Reasoning supports tool use (function calling), allowing it to interact with external tools, APIs, and data sources as part of its response flow.

Does it work with React / Vue / Vanilla JS / Node / etc.?

Yes — the Grok 4 Fast Non-Reasoning API works with any JavaScript framework, Node.js, or plain HTML through Puter.js. Just include the library and start building. See the documentation for more details.

Get started with Puter.js

Add Grok 4 Fast Non-Reasoning to your app without worrying about API keys or setup.

Read the Docs View Tutorials