All Models
Grok 4 Fast
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 Providers (5)
| Provider | Model ID | Input Cost | Output Cost | Context | Max Output | Docs |
|---|---|---|---|---|---|---|
 ZenMux | x-ai/grok-4-fast | $0.20/MTok | $0.50/MTok | 2M | 64K | |
 OpenRouter | x-ai/grok-4-fast | $0.20/MTok | $0.50/MTok | 2M | 30K | |
 Requesty | xai/grok-4-fast | $0.20/MTok | $0.50/MTok | 2M | 64K | |
 NanoGPT | x-ai/grok-4-fast | $0.20/MTok | $0.50/MTok | 2M | 131.1K | |
 xAI | grok-4-fast | $0.20/MTok | $0.50/MTok | 2M | 30K |
Capabilities
Reasoning
Tool Calling
Attachments
Open Weights
Structured Output