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.

Mark Howells-Mead

Adds a hidden field to comment forms, which will subsequently be auto-filled by spam-submitting robots. If the form 
submission contains a value, the comment will not be saved, because only robots will see the field and fill it out.
Simple!
Any form which is processed using the hook <code>comment_form_after_fields</code> (building the form HTML) and <code>preprocess_comment</code> 
(for processing the form submission) will be extended with this functionality.
This plugin doesn’t block or catch any form submissions which have been filled manually in a browser, so you may still 
receive the occasional advertising or sales message as a post or page comment. However, blocking automatically-generated 
spam messages will reduce the number of unwanted messages greatly.

Simplest comment spam catcher

Add a hidden “honeypot” field to comment forms, to help combat comment spam.

LH Zero Spam vs Simplest comment spam catcher