Kasuga

Tiny Comment Spam Blocker is a lightweight yet powerful plugin designed to protect your WordPress comments from spam. It employs five different techniques to detect and block unwanted comments:
<ol>
<li>Nonce Verification – Ensures that the comment form submission is genuine.</li>
<li>Submission Time Check – Blocks comments submitted too quickly to prevent bots.</li>
<li>Honeypot Field – Hidden field that traps automated spam bots.</li>
<li>User Agent Validation – Detects suspicious User-Agent strings and blocks them.</li>
<li>Forbidden Word Filtering – Blocks submissions containing words or phrases from a configurable list within the comment body, email address, or IP address.</li>
<li>JavaScript-Based Human Interaction Detection – Sets a verification token when mouse movement, scrolling, or touch interaction is detected.</li>
<li>(Option) Block Non-Japanese Comments – Blocks comments that do not contain Japanese characters (Hiragana, Katakana, or Han/Kanji), primarily targeting machine-translated or foreign spam.</li>
</ol>
These filters are applied in order: if a comment passes the first check, it proceeds to the second, and so on, until all checks are applied or the comment is blocked.
Additional features:
<ul>
<li>Option to log detected spam in a local log file (up to 1.0 MB).</li>
<li>Optional email notifications when spam is detected.</li>
<li>Easy settings page in the WordPress admin panel.</li>
</ul>
<h3>Settings</h3>
The plugin provides the following settings in the WordPress admin panel:
<ul>
<li>Enable Spam Protection – Toggle the spam protection on or off. When disabled, all anti-spam checks are skipped.</li>
<li>Save Spam Detection Log – Enable or disable logging of detected spam. Logs are saved in a local file up to 1.0 MB within the WordPress uploads directory.</li>
<li>Notification Email Address – Enter an email address to receive notifications when spam is detected. Leave blank to disable email notifications.</li>
<li>Minimum Submission Time (seconds) – Set the minimum allowed time between loading the comment form and submitting a comment. Comments submitted faster than this threshold are considered spam.</li>
<li>Forbidden Words List – Enter one forbidden word, phrase, or IP address per line. Submissions containing these entries in the comment body, email address, or IP address will be blocked. Case is insensitive.
<ul>
<li>Example: 
viagra 
online pharmacy 
spam@email.com 
164.138.205.72</li>
</ul>
</li>
<li>Block No Japanese Comments – If enabled, this becomes the final check: Comments that contain Japanese characters (Hiragana, Katakana, or Kanji) will be automatically accepted after passing other security checks. Comments without Japanese characters will be blocked.</li>
</ul>
<h3>Arbitrary Section</h3>
This plugin is designed to be lightweight and fast, ensuring minimal impact on site performance while providing robust protection against comment spam.

Tiny Comment Spam Blocker

A simple and lightweight yet rock-solid plugin that blocks comment spam using multiple automatic detection methods.

seconet

MioGuard for Contact Form 7 is a lightweight and easy-to-use plugin that protects Contact Form 7 forms from spam and bot submissions using an IP-based rate limit and a customizable honeypot field.
This plugin is not affiliated with or endorsed by the Contact Form 7 team.
Key features: 
– Rate-limit form submissions by IP (configurable from the admin panel; default 5 minutes) 
– Customizable honeypot field to catch bots 
– Optional “Protected by CF7 Simple Guard” badge 
– Fully localized (English + Italian included) 
– No extra database tables, uses WordPress transients with automatic expiration 
– Works with Contact Form 7 forms using Gutenberg or Classic editor 
– Compatible with WordPress 6.0+ and PHP 7.4+
How it works: 
– The plugin blocks repeat submissions from the same IP within the configured interval. 
– The honeypot field prevents automated bots from sending forms. 
– Optionally, you can show a small badge at the end of the form to indicate protection.
Localization 
– English (<code>en_US</code>) and Italian (<code>it_IT</code>) included. 
– Other languages can be added via <code>.po</code> / <code>.mo</code> files in <code>/languages</code>.

MioGuard for Contact Form 7

Spam and bot protection for Contact Form 7 forms with honeypot and rate limiting.

Tiny Comment Spam Blocker vs MioGuard for Contact Form 7