Our verdict on Stable Diffusion
Stable Diffusion is the most flexible AI image option: open models you can run on your own hardware, fine-tune and build into products. It takes more technical effort than Midjourney, but nothing beats it for control and cost at scale.
What is Stable Diffusion?
Stable Diffusion is a family of open-weight text-to-image models developed by Stability AI.
The current flagship is Stable Diffusion 3.5, with Large and Medium versions, alongside widely used SDXL and SD 1.5 models. Because the weights are downloadable, a huge ecosystem of tools, fine-tunes and LoRAs has grown around it.
You can run it locally with interfaces such as ComfyUI or Automatic1111, use it through hosted apps, or call Stability AI's API. Local use means privacy and no per-image cost, but needs a capable GPU and some setup.
The Community License makes models free for commercial use for organisations under $1 million in annual revenue. Larger companies need an Enterprise licence. API credits cost $0.01 each, with images from about $0.03.
Stable Diffusion at a glance
| Made by | Stability AI |
|---|---|
| Launched | 2022 |
| Category | Open AI Image Model |
| Platforms | Local (Windows, macOS, Linux), API, hosted apps |
| Free plan | Yes |
| Pricing | Free models; API from ~$0.03/image |
| Website | stability.ai |
Stable Diffusion key features
Open weights
Download and run models on your own hardware.
SD 3.5 Large and Medium
Strong prompt adherence and image quality.
Fine-tuning and LoRAs
Train custom styles, products or characters.
ControlNet and inpainting
Precise control over pose, layout and edits.
Stability API
Hosted generation priced per credit.
Huge ecosystem
ComfyUI, extensions and community models.
Who Stable Diffusion is best for
Developers
Build image generation into products.
Designers and studios
Custom styles and full control.
E-commerce teams
Product imagery at scale.
Privacy-conscious teams
Generate images entirely on-premise.
Stable Diffusion pros and cons
What we like
- Free, open models
- Maximum control and customisation
- No per-image cost when local
- Massive community ecosystem
What could be better
- Setup and GPU required for local use
- Raw quality can trail Midjourney
- Licensing differs by model and revenue
- Steeper learning curve
Stable Diffusion pricing
Community License
Free commercial use under $1M annual revenue.
API credits
Images from about 3 to 8 credits each.
API membership
About 6,000 credits a month.
Enterprise License
Required above $1M annual revenue.
Running models locally is free apart from your hardware costs. Prices checked November 2026. AI pricing changes often, so confirm on the official Stable Diffusion site.
How to get started with Stable Diffusion
- Choose local (ComfyUI) or the Stability API.
- Download SD 3.5 or get an API key.
- Generate, then refine with inpainting or ControlNet.
Stable Diffusion alternatives
| Tool | Best for | Starting price |
|---|---|---|
| Stable Diffusion | Developers and power users who want open, customisable image models | Free models; API from ~$0.03/image |
| Midjourney | Beautiful images with no setup | From $10/mo |
| FLUX.1 | Open models with excellent quality | Free models |
| Adobe Firefly | Commercially safe images | Free, from $9.99/mo |
| Leonardo AI | Hosted SD-style generation | Free, from $10/mo |
Stable Diffusion FAQ
Is Stable Diffusion free?
Yes. The models are free to download and use, including commercially for organisations under $1 million in annual revenue.
What is the latest Stable Diffusion model?
Stable Diffusion 3.5, available in Large and Medium versions.
Do I need a GPU to run Stable Diffusion?
For local use, yes. Otherwise use the Stability API or a hosted app.
How much does the Stability API cost?
Credits cost $0.01 each, with images from about $0.03.
Sources: Stability AI review 2026 (Fast.io), Stability AI licensing. Reviewed by the Digicrusader editorial team. Compare more options in our directory of 1,000+ AI tools.
