get_the_post_thumbnail_url( int|WP_Post|null $post = null, string|int[] $size = 'post-thumbnail' ): string|false

Compatibility

Present in every tracked release (6.7.7 to 7.1.0), and compiles on PHP 7.4 through 8.6-dev.

Parameters

$postint|WP_Post|nulloptional

Post ID or WP_Post object. Default is global $post.Default: null

$sizestring|int[]optional

Registered image size to retrieve the source for or a flat array of height and width dimensions. Default 'post-thumbnail'.Default: 'post-thumbnail'

Return value

string|false

Post thumbnail URL or false if no image is available. If $size does not match any registered image size, the original image URL will be returned.

Performance profile

How much work a call to get_the_post_thumbnail_url() does, and what it touches: the algorithmic scaling, the Zend instruction count per call across PHP versions, the hooks it hands control to, and the core code that calls it. Measured from the compiled opcodes, not a stopwatch, so every number is identical on any machine running the same PHP version, and every function in core is ranked by cost.

Cost class

Heavy

Reaches the database via get_post().

Scaling

Constant

No loop in the body: the same number of instructions runs whatever you pass in.

Instructions

8–19

Executed per call on PHP 8.5, depending on the branch taken. The body compiles to 20.

Plugin surface

1 hook

Third-party callbacks on 'post_thumbnail_url' run inside this call, and their cost is not bounded by anything here.

Called by

3

3 places in core call this, so the cost is paid more often than your own code shows.

What it touches

• hookthird-party callbacksapply_filters()called directly
• querycontent queryget_post()one call below get_the_post_thumbnail_url()

Further down the call graph this can also reach cache, serialize, option and transient. Those are the worst case, several calls deep and usually down an error path, not what a normal call pays.

What one call costs · 2 distinct outcomes

One number would be a lie: the work depends on which branch runs. These are every distinct cost get_the_post_thumbnail_url() can have, taken from its control-flow graph on PHP 8.5.

Hooks and filters fired · 1

One hook fires while get_the_post_thumbnail_url() runs, in this order:

1. 1
   apply_filters( post_thumbnail_url )filterline 269 (+19 into the body)

   Filters the post thumbnail URL.

Uses · 3

• get_post_thumbnail_id()Retrieves the post thumbnail ID.
• wp_get_attachment_image_url()Gets the URL of an image attachment.
• apply_filters()Calls the callback functions that have been added to a filter hook.

Used by · 3

• render_block_core_cover()Renders the `core/cover` block on server.
• render_block_core_media_text()Renders the `core/media-text` block on server.
• the_post_thumbnail_url()Displays the post thumbnail URL.

Source code

View on Trac ↗View on GitHub ↗

250function get_the_post_thumbnail_url( $post = null, $size = 'post-thumbnail' ) {251	$post_thumbnail_id = get_post_thumbnail_id( $post );252 253	if ( ! $post_thumbnail_id ) {254		return false;255	}256 257	$thumbnail_url = wp_get_attachment_image_url( $post_thumbnail_id, $size );258 259	/**260	 * Filters the post thumbnail URL.261	 *262	 * @since 5.9.0263	 *264	 * @param string|false     $thumbnail_url Post thumbnail URL or false if the post does not exist.265	 * @param int|WP_Post|null $post          Post ID or WP_Post object. Default is global `$post`.266	 * @param string|int[]     $size          Registered image size to retrieve the source for or a flat array267	 *                                        of height and width dimensions. Default 'post-thumbnail'.268	 */269	return apply_filters( 'post_thumbnail_url', $thumbnail_url, $post, $size );270}

Changelog

Introduced in 4.4.0. One change between 6.7.7 and 7.1.0.

1. 6.7.7
2. 6.8.8
3. 6.9.7
4. 7.0.4
5. 7.1.0

Signature, return type and hooks compared across 5 parsed releases.

About this page

Parsed data

Generated from the wordpress-develop 6.9.7 tag, from src/wp-includes/post-thumbnail-template.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.

Corrections

Something wrong on this page? Report it and it gets fixed in the next regeneration.