Grok 4 Fast

xAI • grok-4-fast

Model Information

Slug	grok-4-fast
LLM.txt	View
Release Date	August 28, 2025
AIME 2025	0.92
HLE	0.2
GPQA	0.857
Browse Comp	0.449

Organization

Name	xAI
Website	https://x.ai/

Model Description

Grok 4 Fast is xAI's latest multimodal model with SOTA cost-efficiency and a 2M token context window. It comes in two flavors: non-reasoning and reasoning. Read more about the model on xAI's [news post](http://x.ai/news/grok-4-fast).

Reasoning can be enabled/disabled using the `reasoning` `enabled` parameter in the API. [Learn more in our docs](https://openrouter.ai/docs/use-cases/reasoning-tokens#controlling-reasoning-tokens)

Available at 20 Providers

Provider	Type	Model Name	Original Model	Input ($/1M)	Output ($/1M)	Actions
Routeway		xAI: Grok 4 Fast	`grok-4-fast`	$0.19	$0.48	Model
FastRouter		xAI: Grok 4 Fast	`x-ai/grok-4-fast`	$0.20	$0.50	Model
xAI		Grok 4 Fast	`grok-4-fast`	$0.20	$0.50	Visit
OpenRouter	Chat Code	Grok 4 Fast	`x-ai/grok-4-fast`	$0.20	$0.50	Model
Requesty			`xai/grok-4-fast`	$0.20	$0.50	Visit
ZenMUX		xAI: Grok 4 Fast	`x-ai/grok-4-fast`	$0.20	$0.50	Visit
Mammouth AI	Chat	grok-4-fast	`grok-4-fast`	$0.20	$0.50	Visit
Kilo Code	Code	xAI: Grok 4 Fast	`x-ai/grok-4-fast`	$0.20	$0.50	Visit
MegaNova	Chat	Grok-4-Fast	`x-ai/grok-4-fast`	$0.20	$0.50	Model
Zed	Code	Grok 4 Fast	`Grok 4 Fast`	$0.22	$0.55	Model
WaveSpeed AI	Chat Code	grok-4-fast	`x-ai/grok-4-fast`	$0.22	$0.55	Visit
Nano-GPT		Grok 4 Fast	`x-ai/grok-4-fast`	-	-	Visit
Nano-GPT		Grok 4 Fast Thinking	`x-ai/grok-4-fast:thinking`	-	-	Visit
ValorGPT		Grok 4 Fast	`x-ai-grok-4-fast`	-	-	Model
Yupp	Chat	Grok 4 Fast (OpenRouter)	`x-ai/grok-4-fast`	-	-	Visit
LangDB		grok-4-fast	`grok-4-fast`	-	-	Model
Blackbox AI	Code	blackboxai/x-ai/grok-4-fast	`blackboxai/x-ai/grok-4-fast`	-	-	Visit
Qiniu		x-AI/Grok-4-Fast	`x-ai/grok-4-fast`	-	-	Visit
ApiYI	Chat Code	grok-4-fast	`grok-4-fast`	-	-	Visit
Writingmate	Chat Code	xAI: Grok 4 Fast	`x-ai/grok-4-fast`	-	-	Model

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