How to avoid
spam comments
in blogs?

Often, blog comments
are simply SEO Spam
in a friendly disguise.
There is no remedy available.
But we have some measures.

by | 01.06.2017 | Web & Social Media | 0 comments

“New comment on post: …”,

in the past, this was often an e-mail from our own website which made us smile. Yes! Some reader had found his way to our WordPress site. And more than that, she or he even took the time to write a comment!

Many webmasters take the effort to manually check each comment before allowing it to be published. This has advantages. Those who do not let comments appear right away and automatically can avoid both unobjective comments and spam comments.

But too much control can have a negative impact on an open and dynamic discussion. This is especially the case when controlling a blog is team work. Questions appear. Legal doubts can be resolved quite quickly. Often, it is obvious if a comment is insulting or an attack on someone’s reputation. This can quickly be answered with either yes or no.

Real comment or spam comment?

Another question is much more difficult to resolve: The question if a comment is motivated by somebody’s real interest or if it is merely some undercover marketing measure – a spam comment. Is it the main interest of a comment poster to place a commercial link to his own page or a link to the internet presence of his customer on our website?

These are questions which often cannot be answered with 100 percent accuracy. Often, further research is necessary. It has to be investigated if that comment was really authentic or if it is based on purely commercial intentions.

This process takes time. The person who commented will wonder if the comment will be approved or not, and if not, if this happened intentional or if an administrator simply forgot to take a look at the comment queue and press the green button. That’s ok if we think of a spammer. But it isn’t okay if an interested reader wanted to comment.

The more controversial a blog posting is, the more a website owner is subject to discussions and criticism, the sooner somebody will come up and state: Hey, this is censorship, they are offering people to comment, but they are not approving what they don’t like. That’s a clear disadvantage of manually checking and approving blog comments.

Having to wait for comment approval can stop readers from commenting at all

And generally spoken: Neither bloggers nor companies can have an interest in demotivating readers who want to actively take part in the discussion.

So brave bloggers and webmasters will switch their WordPress installation to the automatic approval of comments. In this case, comments do not have to be approved manually, and there is no waiting. As soon as a new comment is posted, the administrator and the author get an e-mail including the comment which can be deleted right away if it should be of an abusive nature. Personally, I think this is reasonable.

“Auto-approve comments? I would never do that”,

This is an opinion I hear quite often, interesting that especially bloggers frequently state something like that. Ok – somehow, I understand this point of view. Indeed, there is some loss of control – exactly within the period which passes between the automatic acceptance of a comment by WordPress and the moment an administrator gets notice of it by e-mail.

Owners of WordPress blogs who are bold enough to enable automatic comment approval and who decide to simply delete abusive comments after they have already been published have a lot of measures to reduce the attractiveness of the WordPress comment feature especially for spammers.

Filter Plugins like Antispam Bee deliver some basic protection against spam comments which are automatically posted by scripts.

Of course, those plugins’ spam detection quality is not always perfect. You cannot completely rely on them. But perfect reliability is nothing their authors even have promised. Those filter plugins are simply the first line of defense against the big load of spam comments which are posted automatically by spam bot software.

This is a job these plugins sometimes do better, and sometimes, they fail. But one thing is clear to me: These antispam filter plugins really saved me from dealing with thousands of spam comments during the last ten years of blogging. I am thankful for that.

Manually created pseudo comments…

…are a much bigger problem in my point of view. We observed this on our own website and on the corporate blogs of some of our clients. These manual spam comments have been a trend for several years now:

Spammers take the time to text ‘real’ comments…

which only have one goal: To successfully place backlinks to their own website or the sites of their customers. Often, these are kind of sweet talk comments, telling us that our posting is so very competent. To give an example: Under a personal review of a vacuuming robot, somebody comments and shares their personal experience with the product (at least it seems so). As a link to his personal website, he shares an URL leading to an affiliate website which generates revenue by providing come (copy and paste) product information and linking to online shops which sell vacuuming robots. This leads directly to the question:

How should we deal with manually created spam comments?

On the one hand, as a blogger or as a company with a corporate blog, we do not want to be impolite. Why on earth should’nt we approve a comment which is clearly connected to the topic of our posting? On the other hand, we do not really want to allow a comment spammer to be successful, do not want to allow him to generate links for his spammy URL. (Today, spammers are not only interested in follow links, but also in nofollow links.)

So what we need are clear measures which allow us to spoil spammer’s successes with their manually written comments below our precious content.

We can easily achieve this with the following

measures agains comment spam:

  1. Create clear comment guidelines (house rules) and place a link to these rules right above the comment field. State that links to shops, price comparison and affiliate sites and other commercial websites are not allowed on our blog.
  2. If you approve comments automatically: Regularly check all comments, even those who do comply with your rules at first sight. Try to spot links in these comments which are commercial and rigorously eliminate them.
  3. One further escalation step: Do not only delete such links, but replace them with a clear and helpful statement explaining your rules and linking to your comment guidelines.
  4. Of course, we do not have to delete comments just because they were containing commercial links before. Especially if it’s nice ones, we can simply keep these comments online and simply remove those spammy links. Sweet talk stays online, spam goes offline.
  5. Consider including some of the following three commands in the functions.php file of your WordPress Theme (or even better: WordPress child theme). This will lead to a situation in which spammers will have far less fun when trying to spam your blog. Read on to see what will happen:

Spoil those spammers’ game with the WordPress functions.php file:


Do not let links become clickable

The command

remove_filter( 'comment_text', 'make_clickable', 9 );

in the functions.php file of your WordPress theme (or better: child theme) will ensure that WordPress changes its default behavior concerning all links which are posted in your blog’s comments by typing in plain text beginning with http. By default, WordPress will display these links as clickable. By including the command we mentioned above in your functions.php, you instruct WordPress to simply display these links as plain text, not as hyperlinks which can be clicked.


Do not display links to comment authors' websites

The command

remove_filter( 'comment_text', 'make_clickable', 9 );

in your WordPress functions.php file will take care of the URL your comment posters can define as their website. After applying this command, your guests may still enter the URL when posting a comment. But this URL will no longer be displayed on the public front-end along with the comment they posted. This is some really nice surprise for any comment spammer. Personally, I prefer it over simply not displaying the URL field within the comment form (which is also possible to do).


Disallow HTML in comments

The command

add_filter( 'pre_comment_content', 'wp_filter_nohtml_kses' );

in your functions.php will ensure that nobody can use HTML and HTML hyperlinks within comments. If a comment spammer happens to include a link along with a link text masked with “a href”, your WordPress website will still display the link text – but it will not actually display a link.