Grok 4 Fast is an AI model from xAI in the Grok series. Agent Mag tracks its context window, pricing, modalities, and supported API parameters on this page.

How do you use Grok 4 Fast?

Grok 4 Fast can be called through OpenRouter's OpenAI-compatible API using the model ID x-ai/grok-4-fast. This page includes a ready-to-run curl example and the supported parameter list.

Grok 4 Fast is a paid model in the OpenRouter catalog, with separate input and output token pricing shown on this page.

Grok 4 Fast

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xAIGrok

Grok 4 Fast

2M context

$0.200/M input

$0.500/M output

Grok 4 Fast is an AI model from xAI built for agent workflows, with support for text, image, file input and text output. 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...

What is Grok 4 Fast?

Grok 4 Fast is an AI model from xAI that Agent Mag tracks for pricing, context window, modalities, benchmarks, and API compatibility. Builders can use this page to compare Grok 4 Fast against other models for agent workflows and production deployments.

Model ID

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...

Modalities

Input

textimagefile

Output

text

Supported Parameters

include_reasoninglogprobsmax_tokensreasoningresponse_formatseedstructured_outputstemperaturetool_choicetoolstop_logprobstop_p

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