shawfactor

Why should your users prove that they’re humans by filling out captchas? Let bots prove they’re not bots with the <a href="http://lhero.org/plugins/lh-zero-spam/" rel="nofollow ugc">LH Zero Spam plugin</a>.
LH Zero Spam blocks registration spam and spam in comments automatically without any config or setup. Zero Spam was initially built based on the work by <a href="http://davidwalsh.name/wordpress-comment-spam" rel="nofollow ugc">David Walsh</a>, but enhanced with simpler code base and unobtrusive JavaScript.
Major features in LH Zero Spam include:
<ul>
<li>No captcha, because spam is not users’ problem</li>
<li>No moderation queues, because spam is not administrators’ problem</li>
<li>Blocks spam registrations & comments with the use of JavaScript</li>
<li>Blocks buddypress spam registrations with the use of JavaScript</li>
<li>Blocks woocommerce spam orders with the use of JavaScript</li>
</ul>
Like this plugin? Please consider <a href="https://wordpress.org/support/view/plugin-reviews/lh-zero-spam/" rel="ugc">leaving a 5-star review</a>.
Love this plugin or want to help the LocalHero Project? Please consider <a href="https://lhero.org/portfolio/lh-zero-spam/" rel="nofollow ugc">making a donation</a>.

LH Zero Spam

The plugin itself works perfectly and if you like lightweight unobtrusive solutions it is the way to go



Ben Marshalls commenty is unhelpful

Zero Spam makes blocking spam comments and registrations easy.

Arnan

Tired of spam bots in your WordPress and ClassicPress website? Do you want to get rid of false registrations and other spammy nonsense? Don’t wan’t to use a clumsy and user-unfriendly Captcha? Don’t want to use a Captcha from Google or other big-tech company period?
Meet No-Bot Registration, easy to use, superior protection without making it hard for your visitors. Easily blacklist (partial) email addresses and domains so they can no longer register an account.
Create one or more questions and a set of possible answers for them and visitors have to answer your question when they register. 
If they answer wrong, they get denied their account.
Questions can be as simple as “1 + 1”, with possible answers being 1, one or uno. That way you can plan for eventualities and how people interpret your question.
<h4>Features</h4>
<ul>
<li>Protect registration forms</li>
<li>Protect the WooCommerce checkout form if you let people register from there</li>
<li>Protect your blog comment form</li>
<li>Prevents comment spam, trackback spam and other nuisances with ease</li>
<li>Set up multiple security questions to further confuse bots</li>
<li>Blacklist any email, domain or tld you don’t like</li>
<li>Configurable notification messages for users failing the security tests</li>
</ul>

No-Bot Registration

Prevent bots from creating accounts by blacklisting domains and usernames and present people with a human friendly security question.

LH Zero Spam vs No-Bot Registration