/**
 * Filter the upload size limit for non-administrators.
 *
 * @param string $size Upload size limit (in bytes).
 * @return int (maybe) Filtered size limit.
 */
function filter_site_upload_size_limit( $size ) {
	// Set the upload size limit to 10 MB for users lacking the 'manage_options' capability.
	if ( ! current_user_can( 'manage_options' ) ) {
		// 10 MB.
		$size = 1024 * 10000;
	}
	return $size;
}
add_filter( 'upload_size_limit', 'filter_site_upload_size_limit', 20 );