Brandon Fenning

Since the vast majority of WordPress spam is automated in nature, the goal of BotBlocker is to block comment spam bots and not hinder users. This is accomplished through the use of honeypot technology, which tricks the spambot into identifying itself by performing actions that a human could not.
BotBlocker’s features include:
<ol>
<li>Works out of the box to block spam</li>
<li>Automatically stops spam-bots from commenting</li>
<li>Zero hindrance to users: no CAPTCHAS, math questions, passwords or extra input required</li>
<li>Zero false positives and ignores registered users</li>
<li>Can be configured to completely block spam-bots or flag comments as spam</li>
<li>Spam detection messages can be easily adjusted</li>
<li>No javascript or cookies required</li>
<li>Hooks into <code>wp-comments-post.php</code> to prevent spam-bots from directly submitting spam comments</li>
<li>Should work fine with most customized comment forms</li>
<li>No API keys required</li>
</ol>
http://www.lform.com/botblocker/ for more information.
Plugin by <a href="http://www.lform.com/" rel="nofollow ugc">LFORM, a web design company</a> in New Jersey.

BotBlocker

Kills spam-bots, leaves humans standing. No CAPTCHAS, no math questions, no passwords, just spam blocking that stops spam-bots dead in their tracks.

Jack K

<h4>Akismet add-on for Gutenberg Forms plugin</h4>
This add-on let’s you secure your forms from spammers. Akismet checks your contact form submissions against their global database of spam.
This is an add-on plugin and requires <a href="https://gutenbergforms.com/" title="Gutenberg Forms" rel="friend nofollow ugc">Gutenberg Forms</a> plugin to work. Gutenberg Forms is the next generation WordPress form builder plugin.
<h4>How it Works</h4>
Akismet add-on once enabled allow you to add an addditional form action “Akismet”. Once you add that action, you will get a settings pannel for Akismet that let’s you map your form fields with the Akismet fields.
<h4>Get involved with the Development</h4>
If you are a coder and wish to contribute to this Opensource Form Builder and this add-on you are welcome to get involved via Github.
Gutenberg Forms Repo: 
<a href="https://github.com/munirkamal/gutenberg-forms" rel="nofollow ugc">https://github.com/munirkamal/gutenberg-forms</a>
Akismet Add-on Repo: 
<a href="https://github.com/CakeWP/gutenberg-forms-akismet-addon" rel="nofollow ugc">https://github.com/CakeWP/gutenberg-forms-akismet-addon</a>

Gutenberg Forms Add-on for Akismet

Akismet add-on for Gutenberg Forms. Connect with Akismet and protect your form submissions against spam via their global database of spam.

BotBlocker vs Gutenberg Forms Add-on for Akismet