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Grok 4

Default
Grok 4 is xAI's July 2025 reasoning model, trained with scaled reinforcement learning on the Colossus cluster, with native tool use, real-time search, and text and image input. xAI retired the grok-4-0709 slug on May 15, 2026; requests now route to Grok 4.3 with low reasoning effort.
Grok 4 is xAI's July 2025 reasoning model, trained with scaled reinforcement learning on the Colossus cluster, with native tool use, real-time search, and text and image input. xAI retired the grok-4-0709 slug on May 15, 2026; requests now route to Grok 4.3 with low reasoning effort.

Grok 4 is an AI model from xAI, available on ZeroTwo. It has a 256,000-token context window.

Intelligence
Excellent
Speed
Medium
Input
Text, Image
Output
Text

Grok 4 is xAI's July 2025 reasoning model, trained with scaled reinforcement learning on the Colossus cluster, with native tool use, real-time search, and text and image input. xAI retired the grok-4-0709 slug on May 15, 2026; requests now route to Grok 4.3 with low reasoning effort.

256,000 context window
Reasoning token support
Pricing

xAI retired the grok-4-0709 slug on May 15, 2026. Requests to it now route to grok-4.3 and are billed at grok-4.3 rates: $1.25 input and $2.50 output per million tokens below 200,000 prompt tokens, $2.50 and $5.00 at or above that threshold.

Modalities
Text
Input and output
Image
Input only
Audio
Not supported
Endpoints
Chat Completions
v1/chat/completions
Responses
v1/responses
Batch
v1/batch
Realtime
v1/realtime
Assistants
v1/assistants
Fine-tuning
v1/fine-tuning
Embeddings
v1/embeddings
Image Generation
v1/images/generations
Image Edit
v1/images/edits
Speech Generation
v1/audio/speech
Transcription
v1/audio/transcriptions
Translation
v1/translations
Moderation
v1/moderations
Completions (legacy)
v1/completions
Features
Streaming
Supported
Function calling
Supported
Structured outputs
Not supported
Fine-tuning
Not supported
Distillation
Not supported
Fast response
Not supported
Cost efficient
Not supported
Tools
Tools supported by this model when using the Responses API.
Web search
Supported
Code interpreter
Supported
File search
Not supported
Image generation
Not supported
MCP
Not supported
Snapshots
Snapshots let you lock in a specific version of the model so that performance and behavior remain consistent. Below is a list of all available snapshots and aliases for Grok 4.
grok-4-0709

Questions

What is Grok 4's context window?

Grok 4 accepts up to 256,000 tokens of context.

Can I use Grok 4 for free?

You can try Grok 4 on ZeroTwo's free plan, which includes a monthly credit allowance across every model in the catalogue. Heavier use moves to a paid plan rather than a per-token bill.