WordPress does not automatically delete these temporary files. Developers must use unlink() to remove the file once they are finished processing it to avoid cluttering the server's temporary storage.
A notable limitation is that download_url() does not natively support custom HTTP headers, such as Authorization tokens. If you need to download from a private API, you may need a custom wrapper that utilizes wp_remote_get() . download_url wordpress function
require_once( ABSPATH . 'wp-admin/includes/file.php' ); $url = 'https://example.com'; $tmp_file = download_url( $url ); if ( ! is_wp_error( $tmp_file ) ) { // Move the file to a permanent location (e.g., uploads folder) $file_array = array( 'name' => basename( $url ), 'tmp_name' => $tmp_file ); // Further processing with media_handle_sideload() or similar // ... // Always delete the temp file when done unlink( $tmp_file ); } Use code with caution. If you need to download from a private
Use download_url() to get the temporary path. Check for errors: Use is_wp_error() to handle failures. is_wp_error( $tmp_file ) ) { // Move the
Ensure the admin file API is available.
If you are testing locally (e.g., using Docker), ensure your local DNS can resolve external URLs, as this is a frequent cause of download failures. Placeholders and User-Facing Links