# Image Optimization Troubleshooting

This page describes the most common failure scenarios, their causes, and the actions required to resolve them.

## Resolve 415 Unsupported Media Type errors

A **415 – Unsupported Media Type** error occurs when Image Optimization cannot process the requested image.

#### When this happens

Image Optimization returns **415** in the following cases:

* The image file exceeds supported **size or dimension limits**
* The image format is **not supported**
* The image file extension and **Content-Type (MIME type)** do not match

#### Check file size and dimensions

Image Optimization supports images up to a defined size and resolution.

**Limits**

* Maximum file size: **25 MB**
* Maximum dimensions: **3000 × 3000 pixels**

If the image exceeds these limits, the CDN returns **415**.

**How to fix**

* Reduce the image file size
* Resize the image to stay within supported dimensions
* Upload a smaller version of the image to the origin

#### Check supported image formats

Image Optimization supports the following source formats:

* **JPEG**
* **PNG**

Requests for other image formats return **415**.

**How to fix**

* Convert the image to JPEG or PNG before uploading
* Update image URLs to reference a supported format

#### Check Content-Type consistency

A **415** error may occur when the image file extension does not match the **Content-Type** returned by the origin.

**Example**

* File extension: `.png`
* Returned Content-Type: `image/x-ms-bmp`

Although the file extension is supported, the actual media type is not compatible with Image Optimization.

**How to fix**

**Recommended**

Configure the origin or storage to return the correct MIME type.

```
Content-Type: image/png
```

This may require re-uploading the file or updating object metadata in your storage system.

**Temporary workaround**

If the origin cannot be modified immediately, apply a **Page Rule** on the CDN Resource:

* Match path: `*.png`
* Add response header:

  ```
  Content-Type: image/png
  ```

{% hint style="danger" %}
Header overrides do not change the actual file content.\
Ensure that the image format matches its file extension.
{% endhint %}

## Resolve unsupported transformation requests

Some transformation requests may fail even when the source image is valid.

#### Check transformation parameters

Invalid or unsupported transformation parameters may cause the request to fail.

**How to fix**

* Verify that all transformation parameters follow the documented syntax
* Ensure numeric parameters use valid values
* Remove unsupported or conflicting parameters

Refer to the **Image Optimization** documentation for supported modules and parameters.

### Resolve cache-related inconsistencies

Each transformed image URL is cached as a separate object.

If an image was previously cached with incorrect content or headers, unexpected behavior may occur.

#### Clear cached variants

**How to fix**

* Purge the specific transformed image URL
* Re-request the image after correcting the origin configuration

{% hint style="info" %}
Purging the original image URL does not remove transformed variants.\
Each transformed URL must be purged individually.
{% endhint %}

### Verify browser compatibility for WebP

WebP delivery depends on browser support.

If a browser does not support WebP, the CDN serves a fallback format.

This behavior does **not** cause a 415 error.

**How to verify**

* Test the image URL in different browsers
* Inspect the `Content-Type` response header

## When to contact Medianova Support

Contact Medianova Support if:

* The image meets all size, format, and MIME requirements
* The issue persists after cache purge
* The error occurs intermittently across regions

Include the following information when contacting Support:

* Image URL
* CDN Resource name
* Approximate time of the request
* Observed HTTP status code

## Summary

Use this checklist when troubleshooting Image Optimization issues:

* Verify image size and dimensions
* Confirm supported image format
* Ensure correct Content-Type from the origin
* Validate transformation parameters
* Purge cached transformed URLs when needed

Following these steps resolves most Image Optimization errors without additional support.