Grok 4 Fast — Retired model
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
Technical specifications
Frequently Asked Questions
Can I still use the retired Grok 4 Fast model?
No. Grok 4 Fast has been retired and is retained here only as a historical reference. See the active alternatives linked on this page.
Relay integrity checks
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View the full integrity report →Related models and links
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