Grok 4 Fast

Published

Sep 19, 2025

Grok 4 Fast is an AI model developed by xAI (United States), first published in September 2025. It works in the language domain, on tasks such as language modeling/generation, question answering, quantitative reasoning and 3 more.

Epoch AI has no training-compute estimate for this model.

Access: API access. Its weights are not openly released.

Full record

Organization: xAI
Country of organization: United States
Domain: Language
Task: Language modeling/generation, Question answering, Quantitative reasoning, Search, Code generation, Mathematical reasoning
Model accessibility: API access
Open weights: No

Benchmark results

01	WebDev Arena	Arena Score	1149
02	Epoch Capabilities Index	ECI Score	144.6
03	ForecastBench	Overall score	60.5
04	Fictionlivebench	120k token score	0.75
05	ARC-AGI	Score	0.48
06	WeirdML	Accuracy	0.43
07	Cybench	Unguided % Solved	0.3
08	ARC-AGI-2	Score	0.05