Remove Width and Height Attributes from WordPress Images

Code

<?php
/**
 * Remove width and height attributes from images in WordPress content.
 *
 * This function filters the HTML content to remove the width and height attributes
 * from image tags, allowing for more responsive image handling.
 *
 * @param string $content The content of the post.
 * @return string Modified content with width and height attributes removed from images.
 */
function wp_dudecom_remove_image_size_attributes($content) {
    // Use regular expressions to remove width and height attributes from image tags
    $content = preg_replace('/<img(.*?)width=["\']\d+["\'](.*?)>/i', '<img$1$2>', $content);
    $content = preg_replace('/<img(.*?)height=["\']\d+["\'](.*?)>/i', '<img$1$2>', $content);
    return $content;
}

// Add the filter to the content
add_filter('the_content', 'wp_dudecom_remove_image_size_attributes', 10);

/**
 * Remove width and height attributes from post thumbnails.
 *
 * This function filters the HTML output of post thumbnails to remove the width
 * and height attributes, ensuring responsive display.
 *
 * @param string $html The HTML output of the post thumbnail.
 * @return string Modified HTML with width and height attributes removed.
 */
function wp_dudecom_remove_thumbnail_dimensions($html) {
    // Use regular expressions to remove width and height attributes from image tags
    $html = preg_replace('/(width|height)=["\']\d+["\']\s?/', '', $html);
    return $html;
}

// Add the filter to post thumbnails
add_filter('post_thumbnail_html', 'wp_dudecom_remove_thumbnail_dimensions', 10);
add_filter('image_send_to_editor', 'wp_dudecom_remove_thumbnail_dimensions', 10);
?>