doltics

Doltics Radar checks enabled WordPress flows before they complete. Admins can enable protection for outbound email, submitted comments, and account registrations under Settings > Doltics Radar.
Email protection uses WordPress core mail hooks when available. Doltics Radar also includes a Mailgun compatibility adapter for Mailgun versions that replace <code>wp_mail()</code> without calling <code>pre_wp_mail</code>.
<h3>API Contract</h3>
The plugin sends a JSON <code>POST</code> request to the URL <code>https://radar.doltics.com/score</code> :
<pre><code>{
 "text": "The sample text",
 "locale": "en"
}
</code></pre>
The API should return JSON using one of these response shapes:
<pre><code>{
 "score": 0.95,
 "classification": "spam",
 "signals": {
 "token_count": 10,
 "unknown_word_ratio": 0.1,
 "spam_keyword_score": 0.61,
 "uppercase_ratio": 0.34,
 "exclamation_density": 0.3,
 "url_count": 1
 }
}
</code></pre>
Numeric scores are compared against the configured threshold.

Doltics Radar

Protects selected WordPress email, comment, and registration flows with a spam protection API.

Logical Captcha takes advantage of the TextCaptcha.com service, which provides logic-based textual questions instead of distorted images or audio to validate that the entity registering is a real live human being, and not a spam bot. It will provide protection against false registrations and the dreaded spam comments, etc.
An example of such a question might be:
Question: 
Out of a truck, a lion, the color purple, and the number forty-two, which has a door?
Answer: 
truck
Textual logic-based captchas mean that your registration process will be accessible to everyone, including visually/hearing impaired visitors who use access technology to surf the web. It requires a free API key from <a href="http://TextCaptcha.com" rel="nofollow ugc">TextCaptcha.com</a>
This plugin was developed by Josh de Lioncourt of <a href="http://maccessibility.net" rel="nofollow ugc">the Mac-cessibility Network</a>, a site dedicated to blind and visually impaired users of the Mac OS X operating system, the iPhone OS, and other Apple Inc. products and services. Josh de Lioncourt, the Mac-cessibility Network, and related sites are not in anyway affiliated with TextCaptcha.com

Logical Captcha

Integrates a logic captcha to verify that the registrant is a human and not a spam bot instead of using distorted images or audio.

Doltics Radar vs Logical Captcha