PEN BEAM / COPY-READY EXAMPLE
Enqueue a WordPress Stylesheet with Cache Busting
Use filemtime() to version a local theme stylesheet so browsers request updated CSS after a file changes.
What this snippet does
Enqueues a local stylesheet using its modification time as the version, helping browsers request updated CSS after a file changes.
PHP / source code
add_action('wp_enqueue_scripts', 'pb_example_enqueue_styles');
function pb_example_enqueue_styles(): void {
$relative_path = '/assets/css/site.css';
$absolute_path = get_stylesheet_directory() . $relative_path;
$stylesheet_uri = get_stylesheet_directory_uri() . $relative_path;
wp_enqueue_style(
'pb-example-site',
$stylesheet_uri,
[],
is_file($absolute_path) ? (string) filemtime($absolute_path) : null
);
}
Where to place it
Place this code in a child theme functions.php or a site-specific plugin that owns front-end asset registration. Change the file path and handle to match your theme.
Back up the relevant file or settings first. Apply the change on staging, verify behavior, and retain a rollback path before production deployment.
What to check before deploying
- Confirm the path exists in the active child theme; use get_template_directory*() if the asset is intentionally owned by the parent theme.
- Check the Network panel to verify the URL version changes after the stylesheet changes.
- Use a build-generated version for distributed systems where local file modification times may not match across servers.