xAI: Grok 4.1 Fast
Analysis Summary
Grok 4.1 Fast from xAI is built around a large 2M context window and accepts text, images, and files. Tool use and function calling are available, giving it a practical foundation for connected workflows. Its listed prices are low, but the available intelligence index is limited and the provided record does not include detailed coding or agentic benchmark results.
That profile makes it a candidate for high-volume document processing, content support, and workflows that benefit from carrying extensive source material in context. Its multimodal inputs broaden the kinds of materials teams can route through it. For complex reasoning or client-facing decisions, benchmark evidence here is not enough to assume dependable results, so use representative evaluations and human review. The low pricing and long context make it worth piloting as a volume assistant, rather than selecting it as the default for high-stakes work.
Assessed September 23, 2026
Editorial notes
Grok 4.1 Fast offers a 2M context window, image and file input, tool use, and low listed prices; its available intelligence index is limited, so verify quality on demanding tasks.
The DFO score ranks models on the Artificial Analysis Intelligence Index and is refreshed as new models launch. The write-up and verdict are our own. Feedback?
DFO Verdict
Grok 4.1 Fast offers a 2M context window, image and file input, tool use, and low listed prices; its available intelligence index is limited, so verify quality on demanding tasks.
Benchmarks
Artificial Analysis data refreshed Oct 3, 2026. Arena ratings from the Sep 30, 2026 text leaderboard, with style control.
Artificial Analysis has not published coding or agentic results for xAI: Grok 4.1 Fast yet. Until it does, the model sits below tested models on the Coding and AI Agents lists.
How xAI: Grok 4.1 Fast compares
XAI: Grok 4.1 Fast ranks #119 of 433 AI models we track for overall intelligence. Its 2M-token context window is larger than 100% of the models we list. At $0.20 per million input tokens it is cheaper than 52% of comparable models.
Dark bar = input · light bar = output, scaled to the priciest peer.
1M tokens ≈ 8 full-length novels or ~2,500 pages of business documents in a single request.
Pricing
| Token Type | Cost per 1M tokens | Cost per 1K tokens |
|---|---|---|
| Input | $0.20 | $0.000200 |
| Output | $0.50 | $0.000500 |
What would xAI: Grok 4.1 Fast cost your business?
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A website chatbot handling around 100 customer conversations a day, a few short messages each.
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Talk to our teamAbout xAI: 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..
Frequently asked questions about xAI: Grok 4.1 Fast
How much does xAI: Grok 4.1 Fast cost?
xAI: Grok 4.1 Fast costs $0.20 per million input tokens and $0.50 per million output tokens.
What is the context window of xAI: Grok 4.1 Fast?
xAI: Grok 4.1 Fast has a context window of 2,000,000 tokens (2M).
What can xAI: Grok 4.1 Fast do?
xAI: Grok 4.1 Fast supports image/vision input, tool use, and function calling.
Who created xAI: Grok 4.1 Fast?
xAI: Grok 4.1 Fast is developed by xAI and was released on November 19, 2025.