The image_make_intermediate_size WordPress PHP Filter allows you to modify the name of the saved image file when WordPress generates intermediate sizes.
Usage
add_filter('image_make_intermediate_size', 'your_custom_function', 10, 1); function your_custom_function($filename) { // your custom code here return $filename; }
Parameters
$filename
(string) – The name of the saved image file.
More information
See WordPress Developer Resources: image_make_intermediate_size
Examples
Add custom prefix to image filename
Add a custom prefix to the image filename when it’s saved.
add_filter('image_make_intermediate_size', 'add_custom_prefix', 10, 1); function add_custom_prefix($filename) { $custom_prefix = 'custom_'; $new_filename = $custom_prefix . $filename; return $new_filename; }
Add current date to image filename
Add the current date to the image filename when it’s saved.
add_filter('image_make_intermediate_size', 'add_current_date', 10, 1); function add_current_date($filename) { $date = date('Ymd'); $new_filename = $date . '_' . $filename; return $new_filename; }
Convert image filename to lowercase
Convert the image filename to lowercase when it’s saved.
add_filter('image_make_intermediate_size', 'convert_filename_to_lowercase', 10, 1); function convert_filename_to_lowercase($filename) { $new_filename = strtolower($filename); return $new_filename; }
Replace spaces with underscores in image filename
Replace spaces with underscores in the image filename when it’s saved.
add_filter('image_make_intermediate_size', 'replace_spaces_with_underscores', 10, 1); function replace_spaces_with_underscores($filename) { $new_filename = str_replace(' ', '_', $filename); return $new_filename; }
Remove special characters from image filename
Remove special characters from the image filename when it’s saved.
add_filter('image_make_intermediate_size', 'remove_special_characters', 10, 1); function remove_special_characters($filename) { $new_filename = preg_replace('/[^A-Za-z0-9\_\-\.]/', '', $filename); return $new_filename; }