xAI
Grok 4.20
x-ai/grok-4.20
Fast tool calling with a 2M context for very long inputs.
TextText, Images, Files → TextReady on endue
- Agentic work
- Long documents
- Fast replies
Overview
Good for
Written by endue
- Agentic work
- Long documents
- Fast replies
Not ideal for
From the model’s specs
Nothing in the specs rules out common agent work.
Capabilities
| Tool use | Supported |
|---|---|
| Structured output | Supported |
| JSON mode | Supported |
| Reasoning | Supported |
| Vision | Supported |
| Audio input | Not supported |
| Video input | Not supported |
| File input | Supported |
| Long context | Supported |
Specifications
- Model ID
x-ai/grok-4.20- Family
- Grok 4
- Context window
- 2M tokens
- Input
- Text, Images, Files
- Output
- Text
- Knowledge cutoff
- 2026-03
- Released
- 2026-06-10