Skip to main content
Language modelActive

Grok 4.20 Reasoning

xAI

Released
March 10, 2026
Data date
September 8, 2026
Benchmark-Meta-Score
Results from one source only
Speed
105.9 tokens/s
Output throughput
Price
Input · Output / 1M tokens
Input
Text, Image
Output
Text

Grok 4.20 Reasoning is aimed at one controllable, multi-step reasoning and tool-calling run. The model accepts text and images and provides one million tokens of context for substantial working material.

This variant uses the API identifier grok-4.20-0309-reasoning. It separates the single reasoning and tool-calling run from Grok 4.20 Multi-Agent, which is aimed at parallel research. xAI publishes neither weights nor a parameter count.

Specifications and access

SpecificationValue and source
Weights
ProprietarySource
Access
Context window
1,000,000 tokensSource
Notes
1M context, reasoning mode and agentic tool calling, parameter count not disclosedSource
API model ID
grok-4.20-0309-reasoningSource
Source status
activeSource
Release
2026-03-10Source
Maximum output
not statedSource
Input
Text, ImageSource
Output
TextSource
Tool calling
Structured output
Model aliases
grok-4.20-reasoningSource
Reasoning mode
low, medium, highSource