---
id: "22"
slug: "grok-4-fast-models"
date: "2025-09-20"
title: "Grok 4 Fast Models: Flagship and Fast Variants Now Available"
summary: "Added support for Grok 4 Fast Reasoning, and Grok 4 Fast Non-Reasoning models via xAI provider."
image:
  src: "/changelog/grok-4-fast-models.png"
  alt: "Dashboard showing new Grok 4 Fast models via xAI provider"
  width: 1768
  height: 677
---

We're excited to announce support for the latest Grok 4 Fast models through our [xAI provider](/providers/xai).

## ⚡ New Model: Grok 4 Fast Reasoning

Optimized for fast reasoning tasks with excellent performance:

**Model Identifiers**:

- [`grok-4-fast-reasoning`](/models/grok-4-fast-reasoning)

**Context Window**: 256K tokens  
**Max Output**: 256K tokens

**Pricing**:

We're working on dynamic pricing, so these will be the prices by then:

- **Input tokens (<128k)**: $0.20 per 1M tokens
- **Input tokens (≥128k)**: $0.40 per 1M tokens
- **Output tokens (<128k)**: $0.50 per 1M tokens
- **Output tokens (≥128k)**: $1.00 per 1M tokens
- **Cached input tokens**: $0.05 per 1M tokens

**Features**: Vision support, streaming, tool usage, JSON output

Ideal for applications requiring quick reasoning with cost efficiency.

## 🔥 New Model: Grok 4 Fast Non-Reasoning

High-speed model optimized for general tasks without complex reasoning:

**Model Identifiers**:

- [`grok-4-fast-non-reasoning`](/models/grok-4-fast-non-reasoning)

**Context Window**: 256K tokens  
**Max Output**: 256K tokens

**Pricing**:

We're working on dynamic pricing, so these will be the prices by then:

- **Input tokens (<128k)**: $0.20 per 1M tokens
- **Input tokens (≥128k)**: $0.40 per 1M tokens
- **Output tokens (<128k)**: $0.50 per 1M tokens
- **Output tokens (≥128k)**: $1.00 per 1M tokens
- **Cached input tokens**: $0.05 per 1M tokens

**Features**: Vision support, streaming, tool usage, JSON output

Perfect for fast responses and general tasks where reasoning complexity is not required.
