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 using the `reasoning` `enabled` parameter in the API. [Learn more in our docs](https://openrouter.ai/docs/use-cases/reasoning-tokens#controlling-reasoning-tokens)
Prompts and completions on Grok 4 Fast Free may be used by xAI or OpenRouter to improve future models.
by X-ai|2M context|$0.20/M input tokens|$0.50/M output tokens
Endpoints
Available providers for this model, with details on pricing, context limits, and real-time health metrics.
