get_post_thumbnail_id( int|WP_Post $post = null ): int|false
- Since
- 2.9.0, 4.4.0, 5.5.0
- Source
wp-includes/post-thumbnail-template.php:53
Compatibility
- WordPress
- since 5.5.0
- PHP
- 7.4–8.6-dev
- 6.7.7
- 6.8.8
- 6.9.7
- 7.0.4
- 7.1.0
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_Postoptional- Post ID or WP_Post object. Default is global
$post.Default:null
Return value
int|false- Post thumbnail ID (which can be 0 if the thumbnail is not set), or false if the post does not exist.
Performance profile
How much work a call to get_post_thumbnail_id() 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
- Scaling
- Constant
- Instructions
- 7–21
- Plugin surface
- 1 hook
- Called by
- 21
Reaches the database via get_post().
No loop in the body: the same number of instructions runs whatever you pass in.
Executed per call on PHP 8.5, depending on the branch taken. The body compiles to 22.
Third-party callbacks on 'post_thumbnail_id' run inside this call, and their cost is not bounded by anything here.
21 places in core call this, so the cost is paid more often than your own code shows.
What it touches
- querycontent query
get_post()called directly - hookthird-party callbacks
apply_filters()called directly
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_post_thumbnail_id() can have, taken from its control-flow graph on PHP 8.5.
| When | Instructions | Calls it makes |
|---|---|---|
| always | 7 | get_post() |
| always | 21 | get_post(), get_post_meta(), apply_filters() |
Across PHP versions
Compiles the same on PHP 7.4, 8.1, 8.2, 8.3, 8.4, 8.5 and 8.6-dev: 22 instructions, 7–21 executed per call, 1 branch. The work does not change between versions.
An instruction is not a fixed amount of time, so a matching count is not necessarily the same speed; what it rules out is a difference in the work itself.
Hooks and filters fired · 1
One hook fires while get_post_thumbnail_id() runs, in this order:
Uses · 3
- get_post()Retrieves post data given a post ID or post object.
- get_post_meta()Retrieves a post meta field for the given post ID.
- apply_filters()Calls the callback functions that have been added to a filter hook.
Used by · 21
- WP_Media_List_Table::column_title()Handles the title column output.
- WP_REST_Posts_Controller::prepare_item_for_response()Prepares a single post output for response.
- WP_REST_Posts_Controller::prepare_links()Prepares links for the request.
- edit_form_image_editor()Displays the image and editor in the post editor
- get_media_item()Retrieves HTML form for modifying the image attachment.
- get_oembed_response_data_rich()Filters the oEmbed response data to return an iframe embed code.
- get_the_post_thumbnail()Retrieves the post thumbnail.
- get_the_post_thumbnail_caption()Returns the post thumbnail caption.
- get_the_post_thumbnail_url()Returns the post thumbnail URL.
- has_post_thumbnail()Determines whether a post has an image attached.
- prepend_attachment()Wraps attachment in paragraph tag before content.
- render_block_core_cover()Renders the `core/cover` block on server.
Show all 21
- render_block_core_media_text()Renders the `core/media-text` block on server.
- twenty_twenty_one_post_thumbnail()Displays an optional post thumbnail.
- twentyfifteen_post_nav_background()Add featured image as background image to post navigation elements.
- update_post_thumbnail_cache()Updates cache for thumbnails in the current loop.
- wp_playlist_shortcode()Builds the Playlist shortcode output.
- wp_prepare_attachment_for_js()Prepares an attachment post object for JS, where it is expected to be JSON-encoded and fit into an Attachment model.
- wp_xmlrpc_server::_prepare_post()Prepares post data for return in an XML-RPC object.
- wp_xmlrpc_server::mw_getPost()Retrieves a post.
- wp_xmlrpc_server::mw_getRecentPosts()Retrieves list of recent posts.
Source code
function get_post_thumbnail_id( $post = null ) { $post = get_post( $post ); if ( ! $post ) { return false; } $thumbnail_id = (int) get_post_meta( $post->ID, '_thumbnail_id', true ); /** * Filters the post thumbnail ID. * * @since 5.9.0 * * @param int|false $thumbnail_id Post thumbnail ID or false if the post does not exist. * @param int|WP_Post|null $post Post ID or WP_Post object. Default is global `$post`. */ return (int) apply_filters( 'post_thumbnail_id', $thumbnail_id, $post );}Changelog
Introduced in 2.9.0. One change between 6.7.7 and 7.1.0.
Signature, return type and hooks compared across 5 parsed releases.
$post retyped from int|WP_Post to int|WP_Post|null.verified against source$post can be a post ID or WP_Post object.from the docblockAbout this page
- Parsed data
- Generated from the wordpress-develop 6.7.7 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.