Title: image_sideload_extensions
Published: December 9, 2020
Last modified: May 20, 2026

---

# apply_filters( ‘image_sideload_extensions’, string[] $allowed_extensions, string $file )

## In this article

 * [Description](https://developer.wordpress.org/reference/hooks/image_sideload_extensions/?output_format=md#description)
 * [Parameters](https://developer.wordpress.org/reference/hooks/image_sideload_extensions/?output_format=md#parameters)
 * [Source](https://developer.wordpress.org/reference/hooks/image_sideload_extensions/?output_format=md#source)
 * [Related](https://developer.wordpress.org/reference/hooks/image_sideload_extensions/?output_format=md#related)
 * [Changelog](https://developer.wordpress.org/reference/hooks/image_sideload_extensions/?output_format=md#changelog)

[ Back to top](https://developer.wordpress.org/reference/hooks/image_sideload_extensions/?output_format=md#wp--skip-link--target)

Filters the list of allowed file extensions when sideloading an image from a URL.

## 󠀁[Description](https://developer.wordpress.org/reference/hooks/image_sideload_extensions/?output_format=md#description)󠁿

The default allowed extensions are:

 * `jpg`
 * `jpeg`
 * `jpe`
 * `png`
 * `gif`
 * `webp`

## 󠀁[Parameters](https://developer.wordpress.org/reference/hooks/image_sideload_extensions/?output_format=md#parameters)󠁿

 `$allowed_extensions`string[]

Array of allowed file extensions.

`$file`string

The URL of the image to download.

## 󠀁[Source](https://developer.wordpress.org/reference/hooks/image_sideload_extensions/?output_format=md#source)󠁿

    ```php
    $allowed_extensions = apply_filters( 'image_sideload_extensions', $allowed_extensions, $file );
    ```

[View all references](https://developer.wordpress.org/reference/files/wp-admin/includes/media.php/)
[View on Trac](https://core.trac.wordpress.org/browser/tags/7.0/src/wp-admin/includes/media.php#L1055)
[View on GitHub](https://github.com/WordPress/wordpress-develop/blob/7.0/src/wp-admin/includes/media.php#L1055-L1055)

## 󠀁[Related](https://developer.wordpress.org/reference/hooks/image_sideload_extensions/?output_format=md#related)󠁿

| Used by | Description | 
| [media_sideload_image()](https://developer.wordpress.org/reference/functions/media_sideload_image/)`wp-admin/includes/media.php` |

Downloads an image from the specified URL, saves it as an attachment, and optionally attaches it to a post.

  |

## 󠀁[Changelog](https://developer.wordpress.org/reference/hooks/image_sideload_extensions/?output_format=md#changelog)󠁿

| Version | Description | 
| [5.8.0](https://developer.wordpress.org/reference/since/5.8.0/) | Added `'webp'` to the default list of allowed file extensions. | 
| [5.6.0](https://developer.wordpress.org/reference/since/5.6.0/) | Introduced. |

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