Customize allowed HTML Tags in WP Comments

The following snippets will allow you to add html tags that are not allowed by default in WordPress Core. We hook into pre_comment_on_post that runs just before a comment is saved to your database.

Here’s two version of snippets. The first allows one tag to be inserted, the second merges an array of tags you wish to bulk add to the $allowedtags global variable.

Each tag as to be set as the key of the array. The value of that key is another array. You set an empty array if you don’t want or need to add attributes for that tag. Again, each attributes is an array and the value is true to enable that specific attribute for that specific tag. The form is 'attribute' => true,.

On to the examples so it’s more clear. Remember that there are security/spam reasons why tags have been restricted in the comments, so be wise about which tags you allow.

Add One Tag

To add one tag to the $allowedtags array use this next snippet. Here we allow the img tag with src and alt attributes

add_action('pre_comment_on_post', 'add_post_comment_html_tags' );
function add_post_comment_html_tags( $commentdata ) {

  global $allowedtags;

  $allowedtags['img'] = [
    'src'=> true,
    'alt'=> true
  ];

}

Bulk Add Tags

To add multiple tags use this version. Here we add the img tag with the src and alt attributes and the pre tag

add_action('pre_comment_on_post', 'add_post_comment_html_tags' );
function add_post_comment_html_tags( $commentdata ) {

  global $allowedtags;

  $new_tags = [
    'img'=> [
      'src'=> true,
      'alt'=> true
    ],
    'pre'=> []
  ];

  $allowedtags = array_merge( $allowedtags, $new_tags );

}

Remove a Tag From The Allowed List

To remove a tag you wish to restrict from the comments, just use unset() to get the job done. Here’s how to prevent people from posting links in comments. The anchor text will still be shown but the actual link will be stripped from the comment before it’s saved to the database.

add_action('pre_comment_on_post', 'add_post_comment_html_tags' );
function add_post_comment_html_tags( $commentdata ) {

  global $allowedtags;

  unset( $allowedtags['a'] );

}

List of Defaults Tags Allowed

If you want a list of tag allowed by WordPress Core, then here it is. So if it’s not in this list, it’s not allowed by default. Use the snippets above to include more tags.

• a tag
  • href attribute
  • title attribute
• abbr tag
  • title attribute
• acronym tag
  • title attribute
• b tag
• blockquote tag
  • cite attribute
• cite tag
• code tag
• del tag
  • datetime attribute
• em tag
• i tag
• q tag
  • cite attribute
• s tag
• strike tag
• strong tag