set_post_thumbnail_size()WP 2.9.0

Sets the default size of the post thumbnail.

Registers or overrides the parameters of the thumbnail size post-thumbnail, which in WP is used as the post thumbnail.

After setting this function, the thumbnail can be obtained via get_the_post_thumbnail():

echo get_the_post_thumbnail( $page->ID );

This is a wrapper for the function add_image_size() with the preset size name for the thumbnail 'post-thumbnail'. The function exists so that the thumbnail size name does not change - it must remain exactly that.

To be able to define a post thumbnail image, you need to enable this feature with the function: add_theme_support( 'post-thumbnails' ) in the theme file funсtions.php.

To register a new thumbnail size, use add_image_size().

No Hooks.

Returns

null. The function does not return anything.

Usage

set_post_thumbnail_size( $width, $height, $crop );
$width(int)
Width of the thumbnail (in pixels).
$height(int)
Height of the thumbnail (in pixels).
$crop(boolean)
Crop the image (true - a piece of the image will be taken according to the specified dimensions) or simply resize (false - the image will be resized proportionally, the excess will be cut off).
Default: false

Examples

All examples are intended for use in the theme file functions.php.

0

#1 Basic example

Define the use of thumbnails in the template and specify the size of the post thumbnail:

if ( function_exists( 'add_theme_support' ) ) {
	add_theme_support( 'post-thumbnails' );
	set_post_thumbnail_size( 150, 150 );
}
0

#2 Cropping

Resize proportionally: Set the default thumbnail size to 50x50 pixels. The image will be resized by the smallest side. On the larger side, the edges will be cropped.

set_post_thumbnail_size( 50, 50 ); // shrink the picture

Cropping: set the default thumbnail size to 50x50 pixels. The image will be cropped: the central part of the image will be taken with a size of 50x50 pixels:

set_post_thumbnail_size( 50, 50, true ); // cropping

Cropping: Set the default Post Thumbnail size by cropping the image from top left:

// 50 pixels wide by 50 pixels tall, crop from the top left corner
set_post_thumbnail_size( 50, 50, array( 'top', 'left')  ); 

Cropping: Set the default Post Thumbnail size by cropping the image from the center:

// 50 pixels wide by 50 pixels tall, crop from the center
set_post_thumbnail_size( 50, 50, array( 'center', 'center')  ); 

See add_image_size() for more information about cropping.

Note: This function will not resize your existing images. To regenerate existing images in the new sizes, use the Regenerate Thumbnails plugin.

Notes

Changelog

Since 2.9.0 Introduced.

set_post_thumbnail_size() code WP 6.9

function set_post_thumbnail_size( $width = 0, $height = 0, $crop = false ) {
	add_image_size( 'post-thumbnail', $width, $height, $crop );
}