Grok 4.1 Fast
xAI Grok 4.1 Fast — pricing, 2000k context window, API cost calculator and alternatives.
By xAI
Specs
- Provider
- xAI
- Slug
- x-ai/grok-4-1-fast
- Capabilities
- vision, tools, json_mode
Pricing freshness
- Tier
- standard
- Currency
- USD
- As of
- 2026-05-08 17:08 UTC
Pricing history
Tracking Grok 4.1 Fast pricing since 2026-05-08. We'll plot the chart here once it changes.
Quickstart — call Grok 4.1 Fast from your app
curl https://openrouter.ai/api/v1/chat/completions \
-H "Content-Type: application/json" \
-H "Authorization: Bearer $OPENROUTER_API_KEY" \
-d '{
"model": "x-ai/grok-4-1-fast",
"messages": [{"role": "user", "content": "Hello!"}]
}'Official docs: https://openrouter.ai/docs
# pip install openai
from openai import OpenAI
client = OpenAI(
base_url="https://openrouter.ai/api/v1",
api_key=os.environ["OPENROUTER_API_KEY"],
)
resp = client.chat.completions.create(
model="x-ai/grok-4-1-fast",
messages=[{"role": "user", "content": "Hello!"}],
)
print(resp.choices[0].message.content)Official docs: https://openrouter.ai/docs
// npm install openai
import OpenAI from "openai";
const client = new OpenAI({
baseURL: "https://openrouter.ai/api/v1",
apiKey: process.env.OPENROUTER_API_KEY,
});
const resp = await client.chat.completions.create({
model: "x-ai/grok-4-1-fast",
messages: [{ role: "user", content: "Hello!" }],
});
console.log(resp.choices[0].message.content);Official docs: https://openrouter.ai/docs
Related models
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Frequently asked questions
What is Grok 4.1 Fast?
Grok 4.1 Fast is a large language model API from xAI with a 2M-token context window. It costs $0.2 per 1M input tokens and $0.5 per 1M output tokens.
How much does Grok 4.1 Fast cost?
Grok 4.1 Fast is priced at $0.2 per 1M input tokens and $0.5 per 1M output tokens via the xAI API. A 50/50 input/output workload of 1M total tokens costs about $0.35.
What is the context window of Grok 4.1 Fast?
Grok 4.1 Fast supports up to 2M tokens of context per request — roughly 4000 pages of English text or 250000 lines of code at a typical density.
Does Grok 4.1 Fast support vision, tool use, or JSON mode?
Grok 4.1 Fast supports vision, tool/function calling, and structured JSON mode.
Who makes Grok 4.1 Fast?
Grok 4.1 Fast is built and operated by xAI. Pricing, context window, and capabilities on this page are refreshed nightly from xAI's public catalog.
Can I self-host Grok 4.1 Fast?
Grok 4.1 Fast is API-only — its weights are not publicly distributed by xAI, so it cannot be self-hosted today.