What is the context window of x-AI/Grok-Code-Fast 1, and how long can its output be?

The context window of x-AI/Grok-Code-Fast 1 is 256K tokens (256,000), and its maximum output is 10K tokens (10,000).

Can x-AI/Grok-Code-Fast 1 read images, audio, video or PDFs?

No, x-AI/Grok-Code-Fast 1 only accepts text as input, so it cannot read images, audio, video or PDFs.

Does x-AI/Grok-Code-Fast 1 support tool calling?

Yes, x-AI/Grok-Code-Fast 1 supports tool calling (function calling).

Does x-AI/Grok-Code-Fast 1 have a reasoning or thinking mode?

Yes, x-AI/Grok-Code-Fast 1 supports a reasoning mode.

Where does x-AI/Grok-Code-Fast 1 rank on Arena?

Rank 154 on Arena WebDev, with a score of 1164.

What are the closest alternatives to x-AI/Grok-Code-Fast 1?

Qwen3 Max Preview by Alibaba, Seed 1.6 Flash by ByteDance and ERNIE X1.1 by Baidu are the closest alternatives. They were matched on model kind and release date, with no comparable price.

What is the best open-weight alternative to x-AI/Grok-Code-Fast 1?

Kimi K3 is the highest-ranked open-weight model on Arena Text, at rank 19. x-AI/Grok-Code-Fast 1 itself is closed.

Is x-AI/Grok-Code-Fast 1 open source or open weights?

No, x-AI/Grok-Code-Fast 1 is closed, so it is neither open source nor open weights.

Who made x-AI/Grok-Code-Fast 1 and when was it released?

xAI made x-AI/Grok-Code-Fast 1, and it was released on September 2, 2025.

x-AI/Grok-Code-Fast 1

xAI

Announcement

x-AI/Grok-Code-Fast 1

Developer	xAI
Release date	September 2, 2025
Family	Grok
Generation	Grok 1
Level
Context window	256K tokens
Max output	10K tokens
Input	Text
Output	Text
Weights	Closed
Website	x.ai
Links	Model card Docs

Part of a series on

xAI

Context: 256Ktokens
Released: 1y ago

Fast Grok model for responsive chat, reasoning, and tool-assisted work

How it compares

Level

LightweightThe lab's smallest, cheapest and lowest-latency hosted line, built for high volume and simple tasks.

Vs. your stack

Add the models you use to see how this one compares.

Vs. what you use

Better Same Worse

No verdicts yet

Discussion

No comments yet

Be the first to share your thoughts.

Additional source evidence

Source model: xai/grok-code-fast-1
Source family: grok
Last updated: 2025-09-02
Model context: 256K
Model output limit: 10K
Open weights: No
File attachments: No
Reasoning: Yes
Tool calling: Yes
Temperature control: Yes

Complete source record (JSON)

{
  "id": "xai/grok-code-fast-1",
  "name": "x-AI/Grok-Code-Fast 1",
  "description": "Fast Grok model for responsive chat, reasoning, and tool-assisted work",
  "family": "grok",
  "last_updated": "2025-09-02",
  "attachment": false,
  "reasoning": true,
  "tool_call": true,
  "temperature": true,
  "modalities": {
    "input": [
      "text"
    ],
    "output": [
      "text"
    ]
  },
  "limit": {
    "context": 256000,
    "output": 10000
  },
  "release_date": "2025-09-02",
  "open_weights": false
}