---
source: 'https://howaiworks.ai/ai-tools/stable-diffusion'
section: ai-tools
title: Stable Diffusion
description: >-
  The leading open-weights image ecosystem. Stable Diffusion 3.5 ships in Large,
  Large Turbo, and Medium variants under the Stability AI Community License.
category: Image & Art
toolLevel: featured
developer: Stability AI / Open Source Community
projectType: Open Source Model
pricing: Freemium
launchDate: '2022-08-22'
modelUsed: 'Stable Diffusion 3.5 Large, SD 3.5 Large Turbo, SD 3.5 Medium'
officialWebsite: 'https://stability.ai'
pricingPage: 'https://stability.ai'
tags:
  - AI Tool
  - Image Generation
  - Open Source
  - Stability AI
  - Creative
  - Local AI
difficultyLevel: Intermediate
setupTime: 15 minutes
apiAvailable: true
integrationTypes:
  - Web
  - API
  - Local
  - Desktop
  - Mobile
isReviewed: true
lastUpdated: '2026-07-08'
---

# Stable Diffusion

> The leading open-weights image ecosystem. Stable Diffusion 3.5 ships in Large, Large Turbo, and Medium variants under the Stability AI Community License.

Stable Diffusion is a revolutionary open-source AI image generation model that democratizes access to high-quality AI art creation. Unlike proprietary solutions, it can be run locally on personal computers, giving users complete control over their image generation process while maintaining privacy and customization options.

## Overview

Launched in August 2022 by Stability AI, Stable Diffusion represents a breakthrough in open-source AI technology. Built on diffusion models, it generates detailed, high-quality images from text descriptions while being computationally efficient enough to run on consumer hardware.

Stability AI's current Stable Diffusion image release is **Stable Diffusion 3.5**, announced on 22 October 2024, with SD 3.5 Medium following on 29 October 2024. The model's open weights have fostered a vibrant ecosystem of tools, interfaces, and custom checkpoints, making it one of the most versatile and widely-used AI image generation solutions available today.

## Key Features

- **Three SD 3.5 Variants**: **Large** (8.1 billion parameters, generating at 1 megapixel — Stability's most powerful in the family), **Large Turbo** (a distilled version of Large that generates in just 4 steps), and **Medium** (2.5 billion parameters, an improved MMDiT-X architecture, generating at 0.25–2 megapixels and designed to run "out of the box" on consumer hardware).
- **Stability AI Community License**: Free for non-commercial use, and free for commercial use by anyone with **under US $1,000,000 in annual revenue**. Above that threshold, Stability requires an Enterprise License. Users retain ownership of the media they generate.
- **Runs on Consumer Hardware**: Stability designed the SD 3.5 family to be highly customizable for their size and runnable locally.
- **Open Weights**: Weights are downloadable from Hugging Face; inference code is on GitHub.
- **Huge Community Ecosystem**: LoRAs, fine-tuned checkpoints, ControlNets, and node-based workflows built by the community — much of it hosted on Civitai and orchestrated through ComfyUI.
- **Multiple Front-Ends**: AUTOMATIC1111's WebUI, ComfyUI, InvokeAI and Stability's own hosted platform.

## Model Variants

| Variant | Parameters | Notes |
|---|---|---|
| SD 3.5 Large | 8.1B | Generates at 1 MP. Best quality and prompt adherence. |
| SD 3.5 Large Turbo | — | Distilled from Large; inference in 4 steps. Stability does not publish a resolution figure. |
| SD 3.5 Medium | 2.5B | Improved MMDiT-X architecture. Generates at 0.25–2 MP; designed for consumer hardware. |

## How It Works

Stable Diffusion uses a latent diffusion model that operates in a compressed latent space rather than directly on pixel data. This approach makes it much more efficient than previous diffusion models while maintaining high image quality.

**Technical Process:**
1. **Text Encoding**: Your prompt is processed by a text encoder (CLIP)
2. **Noise Generation**: Random noise is created in the latent space
3. **Denoising**: The model iteratively removes noise based on your text prompt
4. **Decoding**: The final latent representation is decoded into a high-resolution image

**Technical Specifications:**
- **Parameters**: 8.1B (SD 3.5 Large), 2.5B (SD 3.5 Medium)
- **Resolution**: 1 MP for SD 3.5 Large; 0.25–2 MP for SD 3.5 Medium. Stability publishes no resolution figure for Large Turbo.
- **Architecture**: MMDiT (Large); MMDiT-X (Medium)
- **Steps**: SD 3.5 Large Turbo is distilled to run inference in 4 steps
- **Supported Formats**: PNG, JPG, WebP
- **Sampling Methods**: DDIM, DPM++, Euler, Heun, and more
- **Licence**: Stability AI Community License

## Use Cases

### Creative & Artistic
- **Digital Art**: Create original artwork and illustrations
- **Concept Art**: Generate ideas for games, movies, and books
- **Character Design**: Develop unique characters and creatures
- **Style Exploration**: Experiment with different artistic styles
- **Portfolio Building**: Create diverse artwork collections

### Professional Applications
- **Marketing Materials**: Generate visuals for campaigns and social media
- **Product Mockups**: Create product images and lifestyle shots
- **Architectural Visualization**: Generate building and interior concepts
- **Fashion Design**: Create clothing and accessory concepts
- **Game Development**: Generate assets and concept art

### Personal Projects
- **Custom Wallpapers**: Create personalized desktop and mobile wallpapers
- **Gift Art**: Generate custom artwork for special occasions
- **Home Decoration**: Create art for interior design projects
- **Educational Content**: Generate illustrations for presentations and learning materials

### Technical & Research
- **Model Training**: Fine-tune models for specific use cases
- **Research**: Study AI image generation techniques
- **API Development**: Build applications using Stable Diffusion APIs
- **Custom Interfaces**: Create specialized tools and workflows

### Advanced Applications
- **Photorealistic Portraits**: Generate high-quality human faces
- **Product Photography**: Create professional product mockups
- **Architectural Visualization**: Design buildings and interiors
- **Scientific Illustration**: Generate diagrams and technical drawings

## Pricing & Access

### Free Options
- **Local Installation**: Free to run on your own hardware
- **Web Interfaces**: Free tiers available on platforms like Hugging Face
- **Open Weights**: Model weights and inference code available for free
- **Community Models**: Thousands of free custom models and checkpoints

### Licensing
- **Non-commercial use**: Free, including scientific research.
- **Commercial use up to US $1,000,000 in annual revenue**: Free. Startups, small and medium businesses, and creators can use the models commercially at no cost, and retain ownership of the media generated.
- **Above US $1,000,000 in annual revenue**: Contact Stability AI for an Enterprise License.

### Paid Services
- **Stability AI Platform API**: Pay-per-generation pricing
- **Cloud Platforms**: Stable Diffusion is also served through third-party cloud providers

### Local Deployment Costs
- **Hardware**: One-time cost for compatible GPU (optional)
- **Electricity**: Minimal ongoing costs for local generation
- **Storage**: Space for models and generated images

## Getting Started

### Option 1: Web Interface (Easiest)
1. Visit [Hugging Face Spaces](https://huggingface.co/spaces) or Stability AI's own platform
2. Find a Stable Diffusion 3.5 interface
3. Enter your text prompt
4. Adjust settings (model, resolution, guidance scale)
5. Click generate and wait for results

### Option 2: Local Installation
1. **Install Python 3.8+** and Git
2. **Install CUDA** (for NVIDIA GPUs) or appropriate drivers
3. **Clone the repository**:
   ```bash
   git clone https://github.com/AUTOMATIC1111/stable-diffusion-webui.git
   cd stable-diffusion-webui
   ```
4. **Install dependencies**:
   ```bash
   ./webui.sh  # Linux/Mac
   webui-user.bat  # Windows
   ```
5. **Download models** from [Hugging Face](https://huggingface.co/models)
6. **Launch the web interface** at `http://localhost:7860`

### Option 3: Desktop Applications
- **InvokeAI**: User-friendly desktop application
- **[ComfyUI](https://howaiworks.ai/ai-tools/comfyui)**: Node-based interface for advanced users
- **NMKD Stable Diffusion GUI**: Simple Windows application

### Best Practices
- **Detailed Prompts**: Be specific about style, composition, lighting, and mood
- **Negative Prompts**: Use to exclude unwanted elements
- **Sampling Settings**: Experiment with different samplers and steps
- **Guidance Scale**: Adjust for more or less adherence to prompts
- **Model Selection**: Try different models for different styles
- **Batch Generation**: Generate multiple variations to find the best result

## Input/Output Examples

### Expected Input
```
Text Prompt: "A majestic dragon flying over a medieval castle at sunset, digital art, highly detailed, fantasy style"
Negative Prompt: "blurry, low quality, distorted, text artifacts"
Settings: Steps: 20, Guidance Scale: 7.5, Sampler: DPM++ 2M, Model: SD 3.5 Large
```

### Expected Output
- PNG image with generation metadata
- SD 3.5 Large outputs at 1 MP; SD 3.5 Medium at 0.25–2 MP

## Limitations

- **Hardware Requirements**: SD 3.5 Large (8.1B parameters) needs substantially more VRAM than SD 3.5 Medium (2.5B)
- **Learning Curve**: Requires understanding of parameters and techniques
- **Quality Variability**: Results can be inconsistent without proper prompting
- **Content Restrictions**: Built-in filters limit certain types of content
- **Processing Time**: Can be slow on lower-end hardware
- **Revenue Threshold**: Commercial use is free only below US $1,000,000 in annual revenue
- **Technical Setup**: Local installation requires technical knowledge

## Alternatives

- **[Midjourney](https://howaiworks.ai/ai-tools/midjourney)** - Premium AI art generator with artistic focus
- **[Runway](https://howaiworks.ai/ai-tools/runway)** - Video and image generation platform

## Community & Support

- **Official Documentation**: [stability.ai](https://stability.ai)
- **Hugging Face**: [huggingface.co/stabilityai](https://huggingface.co/stabilityai) for models and demos
- **Discord**: [Official Stability AI Discord](https://discord.gg/stablediffusion) with active community
- **Reddit**: [r/StableDiffusion](https://www.reddit.com/r/StableDiffusion) for discussions and tips
- **Twitter**: [@StabilityAI](https://twitter.com/StabilityAI) for updates and announcements
- **WebUI Community**: [github.com/AUTOMATIC1111/stable-diffusion-webui](https://github.com/AUTOMATIC1111/stable-diffusion-webui)
- **Model Database**: [Civitai](https://civitai.com) for custom models and checkpoints

## Frequently Asked Questions

### What is Stable Diffusion?

Stable Diffusion is an open-source AI model that generates high-quality images from text descriptions. It's developed by Stability AI and can be used both online and locally on your computer.

### Is Stable Diffusion free to use?

Stable Diffusion 3.5 weights are free to download and run. Under the Stability AI Community License, commercial use is free below US $1,000,000 in annual revenue. Some commercial services charge for API access or premium features.

### How does Stable Diffusion differ from Midjourney?

Stable Diffusion is open-source and can be run locally, while Midjourney is a paid service. Stable Diffusion offers more control and customization options, while Midjourney focuses on artistic quality and ease of use.

### Can I run Stable Diffusion on my own computer?

Yes, you can run Stable Diffusion locally if you have a compatible GPU with at least 4GB VRAM. This gives you complete control and privacy over your image generation.

### What are the system requirements for local installation?

Requirements vary by model. SD 3.5 Medium (2.5B parameters) is designed by Stability to run out of the box on consumer hardware; SD 3.5 Large (8.1B parameters) needs considerably more VRAM. NVIDIA GPUs work best, but AMD and Apple Silicon are also supported.

### How long does it take to generate an image?

Generation time varies widely with hardware, model size and step count. SD 3.5 Large Turbo is distilled to generate in just 4 steps, making it considerably faster than SD 3.5 Large.

### Can I use Stable Diffusion for commercial purposes?

Stable Diffusion 3.5 is released under the Stability AI Community License. It is free for non-commercial use, and free for commercial use by individuals and organisations with less than US $1,000,000 in annual revenue. Above that threshold you need an Enterprise License from Stability AI. Older Stable Diffusion releases carry different licences — check the licence attached to the specific checkpoint you use.

### What file formats does Stable Diffusion support?

Stable Diffusion typically generates PNG images, but can also output JPG, WebP, and other formats depending on the interface you're using.

### How can I improve my image generation results?

Use detailed, specific prompts; experiment with different sampling methods; adjust guidance scale and steps; try different models and checkpoints; and study successful prompts from the community.

### Are there any content restrictions?

Yes, Stable Diffusion has built-in safety filters to prevent generation of harmful content. The exact restrictions vary by platform and implementation.

## Related

### Related tools

- [Midjourney](https://howaiworks.ai/ai-tools/midjourney)
- [FLUX (Black Forest Labs)](https://howaiworks.ai/ai-tools/flux-1)
- [ComfyUI](https://howaiworks.ai/ai-tools/comfyui)
- [Kling AI](https://howaiworks.ai/ai-tools/kling-ai)

---

Source: https://howaiworks.ai/ai-tools/stable-diffusion — HowAIWorks.ai