wp_get_attachment_url() │ WP 2.1.0

Gets the URL of the attachment by the provided attachment ID. Gets the link to the file.

An attachment refers to any file added to the media library: image, archive, video, etc. It does not matter whether the attachment is attached to a post or not.

The function does not modify/clean the obtained URL. If the attachment has incorrect characters in its name or URL, the URL should be cleaned using rawurlencode(). For example, we get the relative path of the file:

$parsed = parse_url( wp_get_attachment_url( $attachment->ID ) );
$url    = dirname( $parsed['path'] ) . '/' . rawurlencode( basename( $parsed['path'] ) );

If you need to get a link to the attachment page, not to the attachment itself, use get_attachment_link().

Uses: get_post_meta(), wp_get_upload_dir()
Used By: image_downsize(), wp_get_attachment_link(), get_header_video_url()
1 time — 0.0009661 sec (slow) | 50000 times — 0.28 sec (very fast) | PHP 7.3.12, WP 5.3.2
Hooks from the function

Returns

String|false. The URL of the attachment or false if the URL could not be obtained.

Usage

wp_get_attachment_url( $attachment_id );
$attachment_id(number)
The ID of the attachment whose URL needs to be obtained.
Default: 0 (current post)

Examples

1

#1 Display the image attached to the post

Let's say we want to display an image attached to post 5. Then first we need to find out the ID of the attachment and then display the image:

// Get the ID of the attachment of post 5
$id = 5;
$attachment_image = get_children( array(
	'numberposts' => 1,
	'post_mime_type' => 'image',
	'post_parent' => $id,
	'post_type' => 'attachment'
) );

// take the first picture out of the array
$attachment_image = array_shift( $attachment_image );

$img = '<img src="' . wp_get_attachment_url( $attachment_image->ID ) . '" alt="" />';

echo $img;

// will return:
// <img src="http://example.com/wp-content/uploads/2011/07/robots.txt.jpg" alt="" />
0

#2 Get the link to the attachment

Let's say we added a picture to the media library and it has an ID 55, then we can get a link to that picture this way:

$image_url = wp_get_attachment_url( 55 );
echo $image_url;

// Returns: http://example.com/wp-content/uploads/image.png
0

#3 Post's thumbnail as a background image 

if( have_posts() ){
	while( have_posts() ){
		the_post();

		if( has_post_thumbnail() ){
			$feat_image_url = wp_get_attachment_url( get_post_thumbnail_id() );

			echo '<div style="background-image:url('. $feat_image_url .');"></div>';
		}
	}
}

Notes

  • Global. String. $pagenow The filename of the current screen.

Changelog

Since 2.1.0 Introduced.

wp_get_attachment_url() code WP 6.8.1

wp-includes/post.php 
function wp_get_attachment_url( $attachment_id = 0 ) {
	global $pagenow;

	$attachment_id = (int) $attachment_id;

	$post = get_post( $attachment_id );

	if ( ! $post ) {
		return false;
	}

	if ( 'attachment' !== $post->post_type ) {
		return false;
	}

	$url = '';
	// Get attached file.
	$file = get_post_meta( $post->ID, '_wp_attached_file', true );
	if ( $file ) {
		// Get upload directory.
		$uploads = wp_get_upload_dir();
		if ( $uploads && false === $uploads['error'] ) {
			// Check that the upload base exists in the file location.
			if ( str_starts_with( $file, $uploads['basedir'] ) ) {
				// Replace file location with url location.
				$url = str_replace( $uploads['basedir'], $uploads['baseurl'], $file );
			} elseif ( str_contains( $file, 'wp-content/uploads' ) ) {
				// Get the directory name relative to the basedir (back compat for pre-2.7 uploads).
				$url = trailingslashit( $uploads['baseurl'] . '/' . _wp_get_attachment_relative_path( $file ) ) . wp_basename( $file );
			} else {
				// It's a newly-uploaded file, therefore $file is relative to the basedir.
				$url = $uploads['baseurl'] . "/$file";
			}
		}
	}

	/*
	 * If any of the above options failed, Fallback on the GUID as used pre-2.7,
	 * not recommended to rely upon this.
	 */
	if ( ! $url ) {
		$url = get_the_guid( $post->ID );
	}

	// On SSL front end, URLs should be HTTPS.
	if ( is_ssl() && ! is_admin() && 'wp-login.php' !== $pagenow ) {
		$url = set_url_scheme( $url );
	}

	/**
	 * Filters the attachment URL.
	 *
	 * @since 2.1.0
	 *
	 * @param string $url           URL for the given attachment.
	 * @param int    $attachment_id Attachment post ID.
	 */
	$url = apply_filters( 'wp_get_attachment_url', $url, $post->ID );

	if ( ! $url ) {
		return false;
	}

	return $url;
}

image (not thumbnails funcs)

wp attachment image

Attachments (Media files)