> ## Documentation Index
> Fetch the complete documentation index at: https://bunny.net/docs/llms.txt
> Use this file to discover all available pages before exploring further.

# Image Classes

> Define reusable transformation presets

Image Classes let you create named presets for Dynamic Images API transformations, making it easier to maintain consistent image styles across your website.

## Why use Image Classes?

Instead of this:

```bash theme={null}
https://yourzone.b-cdn.net/image.jpg?width=300&height=200&quality=85&sharpen=true
```

Use this:

```bash theme={null}
https://yourzone.b-cdn.net/image.jpg?class=thumbnail
```

**Benefits:**

* Consistent transformations across your site
* Easier to update styles (change the class, not every URL)
* Improved cache hit rates
* Enhanced security with forced transformation classes

## Creating Image Classes

**1. Navigate to Image Classes**

Navigate to **Optimizer** → **Image Classes**

![Image Classes overview](https://mintcdn.com/bunnynet-cb9733c2/54-4KCQKoNVNuoyW/images/optimizer/image-classes/image-classes-overview.png?fit=max\&auto=format\&n=54-4KCQKoNVNuoyW\&q=85\&s=dcea4cec9705eb5e8d4fe938f52a7082)

**2. Define your class properties**

Configure the transformation settings for your image class:

* Width, height, aspect ratio
* Quality settings
* Filters and effects
* Any Dynamic Images API parameter

![Add image class properties](https://mintcdn.com/bunnynet-cb9733c2/54-4KCQKoNVNuoyW/images/optimizer/image-classes/image-classes-add-property.png?fit=max\&auto=format\&n=54-4KCQKoNVNuoyW\&q=85\&s=d5478ba65e0d3ad68e3e5017bd2fbab2)

**3. Save the class**

Save the class with a memorable name that describes its purpose (e.g., `thumbnail`, `hero`, `product-mobile`).

## Forced transformation classes

Enable this option to restrict the Dynamic Images API to only use predefined classes:

* Improves cache efficiency (fewer unique transformations)
* Prevents arbitrary transformations (security benefit)
* Returns 403 for invalid or missing classes

This is recommended for production environments where you want tight control over image transformations.

## Example classes

| Property | `thumbnail` | `hero_image` | `mobile_product` |
| - | - | - | - |
| Width | 300px | 1920px | 800px |
| Height | 200px | - | - |
| Aspect Ratio | - | 16:9 | - |
| Quality | 80% | 90% | 75% |
| Additional Settings | Sharpen: true | - | Smart optimization: enabled |


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