xAI: Grok 4.1 Fast
Analysis Summary
xAI Grok 4.1 Fast is a high-throughput general model designed around low-cost, long-context workflows. Its two-million-token context window is the standout feature, complemented by vision, file input, tool use, and function calling. Those capabilities make it practical for large document collections, extended project histories, and automated task routing.
It suits high-volume customer workflows, document processing, research synthesis, and agentic pipelines where context capacity and operating cost matter. The measured intelligence level is below current flagship systems, so complex reasoning, sensitive client copy, and difficult code changes should receive stronger review or escalation. The supplied data also does not include detailed coding benchmarks for this variant.
Its pricing is highly attractive for volume traffic. Use it as a cost-efficient long-context workhorse, with a premium model reserved for ambiguous or high-stakes tasks.
Assessed August 9, 2026
Editorial notes
Grok 4.1 Fast pairs a two-million-token context with vision, file input, tool use, and function calling at very low prices. It is suited to high-volume long-context automation, though its measured intelligence is below premium flagship models.
Rankings consider pricing, capabilities, benchmarks, and real-world applicability and are refreshed as new models launch. Feedback?
DFO Verdict
Grok 4.1 Fast pairs a two-million-token context with vision, file input, tool use, and function calling at very low prices. It is suited to high-volume long-context automation, though its measured intelligence is below premium flagship models.
How xAI: Grok 4.1 Fast compares
XAI: Grok 4.1 Fast ranks #120 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 57% 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.
Strongest on value. The pulled-in technical corner is the trade-off, and if the shape matters more than the price, this is your model.
Compare shapes side-by-side →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.
Full calculator with 748 models → Price Calculator
These numbers get smaller with the right architecture.
We route routine calls to cheap models and save xAI: Grok 4.1 Fast for the hard ones. Most clients cut their estimate by 60-80%.
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.