ProviderXAI
Model idx-ai/grok-4-fast
Context2,000,000 tokens
Pricing$0.20/M input tokens
Use via API
curl https://api.rewind.ai/v1/chat/completions/ \
-H "Authorization: Bearer YOUR_KEY" \
-d '{"model":"x-ai/grok-4-fast"}'
API DocsCompare
Best AI ChatbotsPricing & TokensFAQ
What is Grok 4 Fast?
Grok 4 Fast on Rewind.ai is a free AI tool. There's no charge and no sign up needed to start.
Is Grok 4 Fast really free?
Yes. You get 2,500 free tokens per day to use Grok 4 Fast and every other tool on Rewind.ai. A free account raises that to 5,000 tokens/day. You can buy more starting at $1.
How does Grok 4 Fast work?
Grok 4 Fast runs open-source AI models on our GPU servers. Send your request and the result comes back in seconds.
Do I need to sign up to use Grok 4 Fast?
No. You can use Grok 4 Fast right away without signing up. A free account doubles your daily usage to 5,000 tokens and saves your history.
What are the daily limits for Grok 4 Fast?
Anonymous users get 2,500 tokens/day. Free accounts get 5,000 tokens/day. Tokens reset every 24 hours. Each generation costs ~100-5,000 tokens depending on the operation.
Is my data safe when using Grok 4 Fast?
Your data is processed on our servers and isn't stored permanently unless you choose to save it. We don't sell or share it.
Can I use Grok 4 Fast for commercial purposes?
Yes. Content from Grok 4 Fast is yours to use for personal or commercial work. The AI models we run are commercially licensed.
How does Grok 4 Fast compare to paid alternatives?
Grok 4 Fast matches the quality of paid services because it runs the latest open-source AI models. The difference is you don't pay per use.
What AI model powers Grok 4 Fast?
Grok 4 Fast runs open-source AI models including Qwen 2.5, FLUX and Whisper. We update to newer models as they ship.
Can I use Grok 4 Fast on my phone?
Yes. Grok 4 Fast works in any mobile browser, and the layout adapts to your screen size.
How do I get more tokens?
Sign up for a free account to get 5,000 tokens/day, double the anonymous limit. Or buy token packs starting at $5 for 200,000 tokens. See /pricing/ for all options.
Can I save and share my results?
Yes. After you generate content, you can download it, copy it, or share it via a unique link. Signed-in users can also view their generation history.