Grok 4 Fast: Pricing, Context Window & Benchmarks
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. [Learn more in our docs](https://openrouter.ai/docs/use-cases/reasoning-tokens#controlling-reasoning-tokens)
What you can do with Grok 4 Fast
Everyday Q&A and clear explanations
Writing help (emails, posts, summaries)
Idea generation and brainstorming
Learning support with step-by-step guidance
Composite Indices
Intelligence, Coding, Math
Standard Benchmarks
Academic and industry benchmarks
Benchmark Highlights
| Metric | Value |
|---|---|
| Provider | xAI |
| Context Window | 2,000,000 tokens |
| Input Price | $0.20/1M tokens |
| Output Price | $0.50/1M tokens |
| Release Date | Sep 19, 2025 |
| Modalities | text, image |
| Capabilities | Vision |
Compare Grok 4 Fast to other models
See how it stacks up on price, quality, and overall performance.
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.
Suggested comparisons
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Benchmarks and pricing are sourced from Artificial Analysis where available. OpenRouter specs are used as a fallback.
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