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grok-4-1-fast

Grok 4.1 Fast is xAI’s proprietary AI model, released Nov 19, 2025.

Context
Input
/ 1M
Output
/ 1M
Released
Nov 19, 2025
Modalities

Benchmarks

Scores on standardized evaluations. Higher is better — and rank shows where Grok 4.1 Fast lands among all models tracked on Model Beat.

48.0
Intelligence Index
Epoch AI
48th percentile of tracked models
41.0
Coding Index
Epoch AI
41st percentile of tracked models
47.0
Agentic Index
Epoch AI
47th percentile of tracked models

Reasoning

4 evals
GPQA Diamond85.3%

Graduate-level scientific reasoning

Humanity's Last Exam17.6%

Frontier of human expert knowledge

MMLU-Pro85.4%

Broad expert knowledge

SimpleBench56.0%

Common-sense trick questions

Coding

3 evals
LiveCodeBench82.2%

Contamination-free coding

SciCode44.2%

Scientific research coding

WebDev Arena1223

Human-rated web development

Math

1 evals
AIME 2024/202589.3%

Olympiad-qualifier math

Agentic & Tools

2 evals
APEX12.8%

Multi-step agentic tasks

τ²-bench93.3%

Tool-agent-user reliability

Compare Grok 4.1 Fast with

Frequently asked questions

What is Grok 4.1 Fast?

Grok 4.1 Fast is a Grok-family AI model, from xAI, released Nov 19, 2025.

Who created Grok 4.1 Fast?

Grok 4.1 Fast is an AI model developed by xAI, part of the Grok family, released Nov 19, 2025.

How does Grok 4.1 Fast perform on benchmarks?

On standardized evaluations tracked by Epoch AI, Grok 4.1 Fast scores 85.4% on MMLU-Pro, 93.3% on τ²-bench, 82.2% on LiveCodeBench.

Is Grok 4.1 Fast open source?

Grok 4.1 Fast is a proprietary model (API access), available through its provider's API rather than as a downloadable open-weight model.

Benchmark data from Epoch AI (CC BY) and Artificial Analysis; pricing, specs & descriptions from OpenRouter. Data updated Jul 30, 2026.