10 Characters for Your WordPress Blacklist

Quick WordPress tip for easily and quietly blocking a ton of comment spam. Akismet and other programs are good at catching most spam, but every now and then a bunch of weird, foreign-language spam will sneak past the filters and post live to your site. Here’s a good example of the kind of stuff that’s easy to block:

[ Screenshot: Comment Spam in Moderation ]

This type of spam hits in waves, with similar character patterns running throughout each batch. So you’ll see a bunch of nonsensical spam comments that vary in IP, name, email address, and so on. If other spam mechanisms fail, using WordPress’ built-in anti-spam functionality is a great way to immunize against junk like this:

[ Screenshot: Comment Spam in Moderation ]

We can stop that sort of garbage from scaring away visitors by adding a few lines to your Comment Moderation or Comment Blacklist (both located in your Discussion Settings). Simply add these codes to either list.

The beauty of this technique is its simplicity. WordPress uses regular expressions to scan comments for any of these characters. The comments aren’t deleted, so there’s no real risk, and the chances of someone actually using one of these characters in a real comment is slim to none. What WordPress does with matching comments depends on where you put the list:

  • Added to the Comment Moderation list will result in blocked comments getting sent to the Moderation queue.
  • Added it to the Comment Blacklist will result in blocked comments getting flagged as spam and sent to the Spam bin.

It’s probably safest to add these characters to your Moderation list just in case anything worthwhile happens to show up (it won’t). Once you Save your changes, forget about it. Just monitor (or don’t) your comments as usual and let WordPress’ built-in anti-spam skillz do the work.


Although an elegant and effective technique, you may want to skip using if either of the following apply:

  • You have trackbacks/pingbacks enabled and displaying on your site
  • You allow comments in languages that use any of the blocked glyphs

Otherwise, the list makes an excellent addition to any anti-spam strategy. Especially if you are only using Akismet, this is a great way to further improve the overall security and integrity of your site. For more information and more extensive WordPress blacklists, check these:

Note: To suggest additional characters in the comments, remember to wrap each one with a <code> tag. Thanks :)