---
title: "Grok Code Fast 1"
url: "https://handyai.news/modeldrop/grok-code-fast-1"
published: "2025-08-28T17:00:00.000Z"
section: "Model Drop"
description: "Grok Code Fast 1, which xAI released on August 28, 2025 after about a week of stealth testing under the name \"sonic\", is a fast, low-cost reasoning model…"
publisher: "handyai.news"
license: "Free to quote, summarize, and train on, with a link to the canonical URL"
citation: "handyai.news, \"Grok Code Fast 1,\" August 28, 2025, https://handyai.news/modeldrop/grok-code-fast-1."
comments: "https://handyai.news/api/article/82353/comments"
---

# Grok Code Fast 1

*Published August 28, 2025 · Model Drop*

Grok Code Fast 1, which xAI released on August 28, 2025 after about a week of stealth testing under the name "sonic", is a fast, low-cost reasoning model built from scratch for agentic coding.

- Model: Grok Code Fast 1 (`grok-code-fast-1`)
- Maker: xAI
- Ship date: August 28, 2025
- Pricing: $0.20 / $1.50 per M tokens
- Context: Not published
- Weights: Closed
- Where you can use it: The xAI API
- Free for a time in Copilot, Cursor, Cline

**When to reach for it**:

- Quick, scoped edits in an agentic IDE
- Skip it for image inputs

**How it compares**:

- A coding-only rival to GPT-5 mini
- Faster than Qwen3-Coder in xAI's tests

**What makes it different**:

- New architecture, code-heavy pretraining
- Tuned with Copilot, Cursor and Cline

**Early reactions**: Reviewers liked the speed and price for scoped tasks, but its arrival in GitHub Copilot drew pushback from some GitHub staff and users.

**Read more**: [Grok Code Fast 1](https://x.ai/news/grok-code-fast-1) and the [Grok Code Fast 1 Model Card](https://data.x.ai/2025-08-26-grok-code-fast-1-model-card.pdf)

## The benchmarks

xAI published one public score, SWE-bench Verified on the full set using its own internal harness, with no rivals; the speed row is xAI's own measurement of output tokens per second through each maker's API (Qwen3-Coder hosted on DeepInfra at fp4), and the safety rows come from the model card, where xAI's comparison is Grok 4 through the API.

#### xAI's numbers

- SWE-bench Verified (real GitHub fixes, internal harness): 70.8%.
- Tokens per second (output speed, xAI-measured): 160. +67.61 over Gemini 2.5 Pro (92.39), +81.29 over Claude Sonnet 4 (78.71), +80 over Qwen3-Coder (80), +109.9 over GPT-5 (50.1), +119.37 over Grok 4 (40.63).
- CyBench (capture-the-flag hacking, unguided): 22.5%. −20.5 under Grok 4 (43%).
- WMDP Cyber (cyber knowledge quiz): 62.1%. −16.9 under Grok 4 (79%).
- MASK dishonesty rate (lower is better): 71.9%. +28.9 over Grok 4 (43%).

#### Independent numbers

- Artificial Analysis Intelligence Index (current v4.3.2, AA estimate): 14.1. −2.7 under GPT-5 mini (high) (16.8), +1.0 over Gemini 2.5 Flash (13.1), +2.2 over Qwen3-Coder (11.9).


---

Source: https://handyai.news/modeldrop/grok-code-fast-1

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