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Grok 4

Retired May 2026

xAI's flagship reasoning model, released July 2025 and trained with reinforcement learning at pretraining scale on the Colossus cluster, aimed at complex multi-step tasks.

Context
256K tokens
Cutoff
Released
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Capabilities

What Grok 4 accepts and can do, as published by xAI.

  • Text Accepts and generates natural-language text.
  • Image Accepts images as input alongside text.
  • Reasoning Thinks before it answers, always on or as a switchable mode.
  • Function calling Connect to external tools, APIs, and systems.
  • Structured output Return responses in structured formats like JSON.

Common questions

What is Grok 4 good for?

Multi-step reasoning over text and images. It was xAI's flagship reasoning model from July 2025 until its retirement.

When is Grok 4 not a good fit?

Any new work: xAI retired it in May 2026, and its migration guide points to Grok 4.3 with low reasoning effort. No built-in web search or code execution, and closed weights.

How does Grok 4 compare with Grok 4.3?

xAI describes Grok 4.3 as a fast, reliable model with strong tool calling and instruction following, and it adds a configurable reasoning effort with a no-reasoning setting, which Grok 4 did not offer. Same text and image input. Grok 4 came out 9 months earlier and has a smaller context (256K against 1M tokens).

Can I self-host Grok 4?

No. xAI does not publish the weights; Grok 4 is available only through hosted APIs.

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