Grok 4 Fast

xAI • grok-4-fast

Model Information
Slug grok-4-fast
Release Date August 28, 2025
Aliases grok-4-fast
Organization
Name xAI
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) Context: 2000000

Available at 3 Providers
Provider Input Price ($/1M) Output Price ($/1M) Free
ZenMux $0.20 $0.50
Requesty $0.20 $0.50
OpenRouter $0.20 $0.50
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