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How to Block Spam Comments in WordPress with CAPTCHA

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How to Block Spam Comments in WordPress with CAPTCHA

Comment spam can be a very annoying issue for WordPress beginners. There are may ways to combat comment spam, but if you do not have time to deal with the ever increasing number of spam comments, then there is always an option to block spam comments using CAPTCHA technique. In this article, we will show you how to block spam comments in WordPress with CAPTCHA. We will also discuss the Pros and Cons of using CAPTCHA on your WordPress site.


CAPTCHA is acronym for “Completely Automated Public Turing test to tell Computers and Humans Apart”. It is a technique used to control spam comments submitted by automated bots. It present users with an image containing slightly distorted letters and digits. In order to submit a web form, users need to enter the letters and digits shown in the image to prove that they are human.

Pros of Using CAPTCHA

The most obvious benefit of using CAPTCHA for comments is that it cuts down spam because most spam comments are submitted by automated bots. CAPTCHA prevent bots from abusing your comment form. Combining CAPTCHA technique with Akismet can significantly reduce the number of spam comments on a WordPress site.

Cons of Using Captcha

CAPTCHA is not at all useful in stopping the manually submitted spam comments. A large number of spam comments these days are actually submitted by human users who are trying to add a link to dubious or irrelevant websites in their comments.

Another disadvantage of using CAPTCHA to control spam is that it adds one additional step for users who are commenting on your site. An average user finds it annoying and difficult to fill out CAPTCHA form and may feel less motivated to comment on your site.

If the disadvantages of using CAPTCHA on your comment form seems too much, then perhaps you would want to try blocking spam comments in WordPress using Honeypot.

Implementing CAPTCHA on Your WordPress Comments

There are several WordPress plugins that allow you to add CAPTCHA or reCaptcha challenge to your WordPress comment form. We have handpicked a few of them for you to try on your website.


First thing you need to do is install and activate the WP-reCaptcha plugin on your website. Upon activation, simply go to Settings » WP-reCAPTCHA to configure the plugin.

WP-reCAPTCHA settings

WP-reCAPTCHA requires reCAPTCHA API keys. To generate reCAPTCHA API keys, you need to visit the reCAPTCHA website and sign in using your Google Account. After the signup simply add your site, and it will generate the API Keys for you. You will need to copy and paste those keys into WP-reCAPTCHA Options page.

Generating reCAPTCHA API keys

After entering API keys, you need to check the box next to ‘Enable for comments form’ to activate it for your comment form. WP-reCAPTCHA allows you to hide reCAPTCHA for registered users, choose a color theme, and if your site is open to user registration, then you can also add reCAPTCHA on your registration page. Once you are done with the options, you need to click on ‘Save reCaptcha Settings’ button to store your settings.

reCAPTCHA appearing on  WordPress comment form

That’s all, your comment form is now protected by a reCAPTCHA challenge.

Easy Captcha

If you would like more CAPTCHA options, then install and activate the Easy Captcha plugin. Upon installation, simply go to Settings » Easy Captcha to configure the plugin. It comes with the option to add a hidden Captcha, a simple CAPTCHA, or Google’s recaptcha.

The hidden CAPTCHA is actually similar to honeypot technology. Your human users will not see anything different in their comment form. However, bots will be caught by the plugin.

Simple CAPTCHA adds the usual image based CAPTCHA, but this one is easier for your users to read and fill. Lastly, you can also use Google’s reCAPTCHA as well.

Easy Captcha Settings

It also allows you to add CAPTCHA to not just comment form, but also to registration, login, and password reset pages. Once you have configured the plugin settings, save your changes and preview your comment form.

Easy Captcha Comment Form


For more powerful options, try the Securimage-WP plugin. Upon installation simply go to Settings » Securimage-WP to configure the plugin.

Unlike previous plugins mentioned in this article, Securimage-WP has lots of options, which would probably look a bit overwhelming to a beginner level user.

Securimage-WP Settings

Securimage-WP does not use Google’s reCAPTCHA. Instead, it generates your own captcha image using php GD image library. It also has the option to add a refresh button and to display audio captcha button. These options are really very helpful for users with special needs.

Captcha generated by Securimage-WP with audio and refresh buttons

When using Securimage-WP don’t forget to uncheck the box next to ‘Show “Protected By” Link’. Otherwise it will show a link back to plugin’s website.

We hope this article helped you block spam comments in WordPress with CAPTCHA. If you liked this article, then follow us on Twitter and Google+.

Editorial Staff at WPBeginner is a team of WordPress experts led by Syed Balkhi. Page maintained by Syed Balkhi.

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  1. Natalie VK says:

    I doubt this will protect from spam. May be from unsophisticated bots, but that’s all.

  2. furi says:

    So what i should use to prevent spam?

  3. Aaron Crow says:

    What cracks me up are the number of people spamming their product on this “block spam” blog post. Sigh it never ends…

  4. Rick says:

    Captchas don’t work. And they are a pain for users. I’ve developed a proven technique, and it works in WP Contact forms and other PHP pages. It is free to use (open source), and I have found that form spam just stops dead when I implement it on web sites.
    All free, no ads, and I delete any emails I get requesting information. It’s all here . The technique works.

  5. Stuart K says:

    It’s the spammers that cause the problems, but captcha-type solutions make it a pain for your regular users to post comments.

    On WordPress, I use It seems to have eliminated all the spam, and my users don’t have to jump through hoops to comment.

    • WPBeginner Support says:

      We agree that commenting should be made easier for users. The plugin you mentioned uses the same technique we mentioned in the cons of using captcha.

    • Andrew says:

      It is very easy for a bot to pass the Anti-Spam plugin. Most of the spam tools can be configured not to fill some inputs or fill a fixed value in other inputs. You should add a hidden field and modify its value trough Ajax…

  6. Hafeez says:

    thanks for nice info. How I can add Capchta in contact us form?

  7. Emanuele says:

    We are using Keypic, from then we fixed the spam problem

  8. Leonardo Peixoto says:

    Hello, this is a great blog, congratulations. I installed the floating social bar in my blog, but I would like it stay like yours. How can I leave it like yours? Can you send me the style CSS? Thanks.

  9. Simon says:

    What about SweetCaptcha?

  10. Corey Freeman says:

    I personally like using “Conditional Capchta” because then it only shows to spammers. Less annoyance but the same amount of protection :)

    • Crissie says:

      According to a forum moderator’s reply of just yesterday (4/15/14), Conditional Captcha and all other apps like it are totally WORTHLESS. Apparent reason why is because hackers came up with code or other means to defeat captchas the same day they hit the IT market! …

      As my ex-husband is so fond of saying, “Anything the mind of one man can do, another one can UNDO.” So true, so true. If that’s the case, though (and we all know it IS), what’s really the point of ANY security software or plug-in?

      Sorry for rambling, just wanted to give you a heads up about capcthas, per expert advice.

      • security master says:

        You are right, but the point of adding a security software to make it harder for the common person.

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