I'm suffering from the issue of lots of fake registrations for my site.
I'd like to add a captcha for registrations. What is the best plugin that will require a captcha at registration? Recommendations based on real installs are most appriciated!

Also: I'm using the most up-to-date install of WP.

7 Answers 7


My favorite captcha plugin is reCaptcha. The captcha images are scans from old, damaged books. A computer identifies possibilities with OCR, then the user, in correctly filling out the captcha, confirms it. It helps digitize whole books this way.

It's an initiative by Google. Read about them on their website.

  • isn't this a captcha for comments only? I didn't see registration mentioned
    – Lea Cohen
    Commented Mar 28, 2011 at 11:10
  • @Lea, it seems so. Here's a version cooked up by someone which works for registration. Sorry about that. wordpress.org/extend/plugins/wp-recaptcha Commented Mar 29, 2011 at 1:07

Update: From my hard-earned and painful expereince, KeyCAPTCHA is a scam by professional spammers

keycaptcha.com site has live online demo and it serves not only WordPress/BuddyPress powered websites but all PHP5-based CMSs. It is specially designed that in case of being cracked, pool of captchas and even its type (of interactivity for passing) can be changed without plugin reinstall

Other unique features worth to mention:

SI Captcha and reCAPTCHA (recommended in one of answers in this thread) are easily passable by spam bots


I actually recommend not using a traditional captcha at all.

Many usability studies show that complex or image based captchas reduce sign ups by a whopping 25-60% depending on complexity.

The alternatives are: http://wordpress.org/extend/plugins/registrap/

Using simple math question http://wordpress.org/extend/plugins/block-spam-by-math/

Personally I use 1 hidden field and it works like a charm and no need to squint and some lame image.

  • I rejected edit by Pwn of this answer since I don't feel answer edits are appropriate discussion technique (comments are). But he had (seemingly) valid point that plugins in this answer mostly relate to comments spam, while original question is about registration spam.
    – Rarst
    Commented Mar 25, 2011 at 20:03
  • PS I've opened topic on meta Are low-rep edits inappropriate as discussional tool? to check if my decision was correct.
    – Rarst
    Commented Mar 25, 2011 at 20:11
  • I went ahead and deleted the plugins I listed, I read the OP wrong, sorry, still an applicable idea though.
    – Wyck
    Commented Mar 26, 2011 at 3:15
  • 1
    Agree that captcha is a poor solution - take a look at this post 90percentofeverything.com/2011/03/25/fk-captcha
    – anu
    Commented Mar 26, 2011 at 9:47

That depends. Do you have a custom registration page in your template, or are you using the default WordPress registration page? Or the Buddypress registration page maybe?

Have a look at SI Captcha as it supports both. http://wordpress.org/extend/plugins/si-captcha-for-wordpress/

OR if you want a cleaner looking captcha try WP-Recaptcha (API key required- free) http://wordpress.org/extend/plugins/wp-recaptcha/

I've used both and haven't had any spam sign ups yet! ... as further security you could install ban-hammer and enable stopforumspam feature that auto-blocks any e-mails on the blacklist from registering!! (do a google search for wordpress banhammer plugin... i'd link you but it won't let me post more than 2 links)


i like SweetCaptcha.com , they have Wordpress and Joomla plugins here is the wordpress: http://wordpress.org/extend/plugins/sweetcaptcha-revolutionary-free-captcha-service/


The one plugin all my clients love (for unknown reason) is KeyCAPTCHA - Free interactive CAPTCHA service (that is the real name). I like it because it integrates with :

  • Registration form
  • Comment form
  • Login form
  • Lost password form
  • Contact Form 7
  • BuddyPress

Cartpauj Register Captcha works very well for me: http://wordpress.org/extend/plugins/cartpauj-register-captcha/

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