Grok 4 Fast

by xAI

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.

Chat with Grok 4 Fast

Input Price$0.20/1M tokens

Output Price$0.50/1M tokens

Intelligence34.9

Coding27.4

Specifications

Technical details and pricing.

ProviderxAI

Context Window2,000,000 tokens

Release DateSep 19, 2025

ModalitiesText, Image → Text

CapabilitiesVision

Benchmarks

10 benchmark scores from Artificial Analysis.

GPQA84.7%

MMLU Pro85.0%

HLE17.0%

LiveCodeBench83.2%

AIME 202589.7%

SciCode44.2%

LCR64.7%

IFBench50.5%

Tau265.8%

TerminalBench Hard18.9%

Composite Indices

Intelligence, Coding, Math

Standard Benchmarks

Academic and industry benchmarks

Frequently Asked Questions

What is Grok 4 Fast good for?

Use Grok 4 Fast for everyday tasks like writing, summarizing, brainstorming, and getting clear explanations.

How much does Grok 4 Fast cost?

Pricing is based on usage. Current rates are $0.20/1M tokens for input and $0.50/1M tokens for output.

Can I try Grok 4 Fast for free?

Yes. You can start a chat instantly and test the model before deciding on a plan.

Does Grok 4 Fast support images or audio?

Grok 4 Fast can understand images.

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Benchmarks and pricing are sourced from Artificial Analysis where available. OpenRouter specs are used as a fallback.