xAI: Grok 4.1 Fast
Analysis Summary
Grok 4.1 Fast is xAI's budget-tier offering, priced at $0.20 input and $0.50 output per million tokens with a 2 million token context window. Its intelligence index of 16.9 and coding index of 19.5 place it well below the competitive tier for demanding tasks. Agentic performance at 39.1 is modest, and instruction-following scores are low.
The 2M context window is a genuine differentiator for bulk document ingestion or long-thread summarisation at low cost. Tool use, function calling, and vision are all supported, giving it reasonable capability breadth for a budget model. However, reasoning depth and coding reliability are insufficient for complex autonomous workflows or software engineering tasks.
At this price point, Grok 4.1 Fast suits high-volume, low-complexity tasks where cost per call matters more than answer quality. Businesses needing reliable reasoning or agentic execution should use a higher-tier model.
Assessed June 17, 2026
Editorial notes
Grok 4.1 Fast from xAI offers a 2M token context window and very low pricing, but benchmark performance across reasoning, coding, and agentic tasks is limited, making it better suited to lightweight or high-volume use cases.
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Performance Profile
How xAI: Grok 4.1 Fast compares
XAI: Grok 4.1 Fast ranks #75 of 380 AI models we track for overall intelligence, #70 of 292 for agentic tasks. 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 53% of comparable models.
About 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..
Capabilities
Performance Indices
Source: Artificial Analysis
Benchmark Scores
Intelligence
Technical
Content
Benchmark data from Artificial Analysis and Hugging Face
How does xAI: Grok 4.1 Fast stack up?
Compare side-by-side with other specialist models.
Model Information
| OpenRouter ID |
x-ai/grok-4.1-fast
|
| Provider | x-ai |
| Release Date | November 19, 2025 |
| Context Length | 2,000,000 tokens |
| Max Completion | 30,000 tokens |
| Status | Active |
Pricing
| Token Type | Cost per 1M tokens | Cost per 1K tokens |
|---|---|---|
| Input | $0.20 | $0.000200 |
| Output | $0.50 | $0.000500 |
Leaderboard Categories
External Resources
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.
