Grok 4.1 Fast
xAI • LLM
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...
Specifications
Context Window
2.0M tokens
Input Price/1M
—
Output Price/1M
—
Parameters
—
Max Output
30K tokens
Benchmarks
Grok 4.1 Fast results on the main AI model evaluation benchmarks. Higher scores indicate better performance.
Agentic
| Benchmark | Score | Maximum | Methodology |
|---|---|---|---|
| Terminal-Bench Hard | 24.0 | 100.0 | — |
Coding
| Benchmark | Score | Maximum | Methodology |
|---|---|---|---|
| LiveCodeBench | 82.0 | 100.0 | Artificial Analysis official API |
| LiveBench Coding | 54.3 | 100.0 | Contamination-free benchmark with objective ground-truth answers |
| SciCode | 44.0 | 100.0 | — |
| AA Coding Index | 30.9 | 100.0 | Artificial Analysis official API |
Data Analysis
| Benchmark | Score | Maximum | Methodology |
|---|---|---|---|
| LiveBench Data Analysis | 40.6 | 100.0 | Contamination-free benchmark with objective ground-truth answers |
Knowledge
| Benchmark | Score | Maximum | Methodology |
|---|---|---|---|
| MMLU-Pro | 85.0 | 100.0 | — |
Language
| Benchmark | Score | Maximum | Methodology |
|---|---|---|---|
| LiveBench Language | 50.0 | 100.0 | Contamination-free benchmark with objective ground-truth answers |
Long Context
| Benchmark | Score | Maximum | Methodology |
|---|---|---|---|
| AA-LCR | 68.0 | 100.0 | — |
Math
| Benchmark | Score | Maximum | Methodology |
|---|---|---|---|
| AA Math Index | 89.3 | 100.0 | Artificial Analysis official API |
| AIME 2025 | 89.0 | 100.0 | Artificial Analysis official API |
| LiveBench Math | 38.9 | 100.0 | Contamination-free benchmark with objective ground-truth answers |
overall
| Benchmark | Score | Maximum | Methodology |
|---|---|---|---|
| LiveBench Global | 33.5 | 100.0 | Contamination-free benchmark with objective ground-truth answers |
| AA Intelligence Index | 30.6 | 100.0 | Artificial Analysis official API |
Reasoning
| Benchmark | Score | Maximum | Methodology |
|---|---|---|---|
| MMLU Pro | 85.4 | 100.0 | Artificial Analysis official API |
| GPQA Diamond | 85.0 | 100.0 | Artificial Analysis official API |
| IFBench | 53.0 | 100.0 | — |
| LiveBench Reasoning | 23.4 | 100.0 | Contamination-free benchmark with objective ground-truth answers |
| HLE | 18.0 | 100.0 | — |
Tool Use
| Benchmark | Score | Maximum | Methodology |
|---|---|---|---|
| Tau²-Bench | 93.0 | 100.0 | — |
Information
- Release date
- November 19, 2025
- Tool Calling
- ✅ Supported
- Vision
- ✅ Supported
- Audio
- ❌ Not supported
Full Analysis: Grok 4.1 Fast
What is Grok 4.1 Fast?
Grok 4.1 Fast is an AI model developed by xAI, classified as a large language model (LLM). It is a multimodal model, capable of processing text, images, and potentially other media types. As a proprietary model, it is available via xAI's cloud API. With a context window of 2.0M tokens, it is suitable for processing long documents such as contracts, books, and complete codebases.
Pricing & Costs in 2026
Grok 4.1 Fast does not have public per-token pricing available at this time. Some models offer access via enterprise plans or research programs. Check xAI's official website for up-to-date availability and pricing.
Benchmarks & Performance
Grok 4.1 Fast was evaluated on 20 different benchmarks, covering categories like Agentic, Coding, Data Analysis, Knowledge, Language, Long Context, Math, overall, Reasoning, Tool Use. Results show exceptional performance across available evaluations.
It's important to note that benchmarks measure specific aspects and don't capture the full user experience. Factors like instruction adherence, behavior in long conversations, and real-world task quality vary significantly between models and aren't always reflected in standard scores.
Recommended Use Cases
Grok 4.1 Fast is suitable for a wide range of AI applications: long document analysis (contracts, legal proceedings, codebases), automation with tool calling (API integration, databases, external systems), image and visual document analysis (OCR, diagrams, screenshots), multimodal processing combining text and images, complex reasoning, math problem solving, and logical analysis, text generation, summarization, translation, and general assistance.
Comparison with Alternatives
In the 2026 AI model ecosystem, Grok 4.1 Fast competes directly with similarly capable models. xAI competes in this segment against OpenAI, Anthropic, Google, and Meta. The choice between models depends on the specific use case, budget, latency requirements, and need for features like multimodality and tool calling.
For a detailed side-by-side comparison, use our comparison tool or check the overall model ranking.
Frequently Asked Questions
What is 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...
How much does Grok 4.1 Fast cost?
Grok 4.1 Fast does not have public per-token pricing available at this time. Check xAI's official website for up-to-date information.
How does Grok 4.1 Fast compare with other models?
In available benchmarks, Grok 4.1 Fast scored: Terminal-Bench Hard: 24/100, LiveCodeBench: 82/100, LiveBench Coding: 54.26/100. See the full table above for a detailed comparison.
Is Grok 4.1 Fast open source?
No, Grok 4.1 Fast is a proprietary model from xAI. It is available via cloud API. For open source alternatives, check our open source model ranking.
What is Grok 4.1 Fast best for?
Grok 4.1 Fast excels at complex reasoning and problem solving. With its large context window, it handles long documents, codebases, and extended conversations. It supports tool calling for API integrations and automation.
Last updated: July 17, 2026 • View methodology →