Grok 4 Fast
LegacyAffordableFast version of Grok 4 with SOTA cost-efficiency and 2M-token context.
Multimodal model supporting both reasoning and non-reasoning modes. Predecessor to Grok 4.1 Fast.
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Grok 4 Fast by xAI has a Capability Index of 77.0, making it comparable to the field average. It ranks #36 out of 92 models on the idapt capability leaderboard. The model supports vision/image input, a 2M context window.
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Nemotron 3 Ultravs Grok 4 FastFrequently Asked Questions about Grok 4 Fast▼
Who created Grok 4 Fast?
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Grok 4 Fast was created by xAI.
How capable is Grok 4 Fast?
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Grok 4 Fast has a Capability Index of 77.0/100, making it comparable to the field average. It ranks #36 out of 92 models.
Is Grok 4 Fast a reasoning model?
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No, Grok 4 Fast is not a reasoning model. It responds directly without an extended internal thinking step. For tasks requiring deep chain-of-thought reasoning, consider models like Claude, o-series from OpenAI, or Gemini Thinking.
Does Grok 4 Fast support image or vision input?
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Yes, Grok 4 Fast supports vision/image input. You can share images in your conversation and the model will analyze and respond based on their content.
Does Grok 4 Fast support audio?
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No, Grok 4 Fast does not support audio input.
What is the context window of Grok 4 Fast?
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Grok 4 Fast has a context window of 2M tokens, meaning it can process approximately 1,500,000 words of context at once.
Is Grok 4 Fast open source?
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Grok 4 Fast is a proprietary model developed by xAI. The model weights and training data are not publicly available.
What is Grok 4 Fast good at?
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Based on benchmark data, Grok 4 Fast excels at: visual analysis and image understanding. It is xAI's capable model suitable for a wide range of tasks.
Where can I use Grok 4 Fast?
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You can chat with Grok 4 Fast on idapt.app — no separate API key required. idapt is an AI workspace with 200+ models, agents, computers, and tasks. You can also access Grok 4 Fast through xAI's own API or platform.