Takayuki Miyoshi

<p>Really Simple CAPTCHA does not work alone and is intended to work with other plugins. It is originally created for <a href="https://contactform7.com/" rel="nofollow ugc">Contact Form 7</a>, however, you can use it with your own plugin.</p>
<p>Note: This product is “really simple” as its name suggests, i.e., it is not strongly secure. If you need perfect security, you should try other solutions.</p>
<h4>How does it work?</h4>
<p>Really Simple CAPTCHA does not use PHP “Sessions” for storing states, unlike many other PHP CAPTCHA solutions, but stores them as temporary files. This allows you to embed it into WordPress without worrying about conflicts.</p>
<p>When you generate a CAPTCHA, Really Simple CAPTCHA creates two files for it; one is an image file of CAPTCHA, and the other is a text file which stores the correct answer to the CAPTCHA.</p>
<p>The two files have the same (random) prefix in their file names, for example, “a7hk3ux8p.png” and “a7hk3ux8p.txt.” In this case, for example, when the respondent answers “K5GF” as an answer to the “a7hk3ux8p.png” image, then Really Simple CAPTCHA calculates hash of “K5GF” and tests it against the hash stored in the “a7hk3ux8p.txt” file. If the two match, the answer is confirmed as correct.</p>
<h4>How to use with your plugin</h4>
<p>Note: Below are instructions for plugin developers.</p>
<p>First, create an instance of ReallySimpleCaptcha class:</p>
<pre><code>$captcha_instance = new ReallySimpleCaptcha();
</code></pre>
<p>You can change the instance variables as you wish.</p>
<pre><code>// Change the background color of CAPTCHA image to black
$captcha_instance->bg = array( 0, 0, 0 );
</code></pre>
<p>See really-simple-captcha.php if you are interested in other variables.</p>
<p>Generate a random word for CAPTCHA.</p>
<pre><code>$word = $captcha_instance->generate_random_word();
</code></pre>
<p>Generate an image file and a corresponding text file in the temporary directory.</p>
<pre><code>$prefix = wp_rand();
$captcha_instance->generate_image( $prefix, $word );
</code></pre>
<p>Then, show the image and get an answer from respondent.</p>
<p>Check the correctness of the answer.</p>
<pre><code>$correct = $captcha_instance->check( $prefix, $the_answer_from_respondent );
</code></pre>
<p>If the $correct is true, go ahead. Otherwise, block the respondent — as it would appear not to be human.</p>
<p>And last, remove the temporary image and text files, as they are no longer in use.</p>
<pre><code>$captcha_instance->remove( $prefix );
</code></pre>
<p>That’s all.</p>
<p>If you wish to see a live sample of this, you can try <a href="https://contactform7.com/captcha/" rel="nofollow ugc">Contact Form 7</a>.</p>


Really Simple CAPTCHA

Needed this for an installation with custom forms. I used the plugin developers instructions and was able to make a fully custom implementation based on server side validation within 30 minutes. No more spam bots misusing the forms. Thank you!

Great work - easy to implement

Really Simple CAPTCHA is a CAPTCHA module intended to be called from other plugins. It is originally created for my Contact Form 7 plugin.

Freemius

Melapress

WPWhiteSecurity

WPKube

<h4>IMPORTANT NOTICE</h4>
<p>CAPTCHA 4WP has been acquired by WPKube. <a href="https://melapress.com/captcha-4-wp-plugin-acquired-by-wpkube/" rel="nofollow ugc">Read the announcement</a> for more information.<br />
We, at Melapress, would like to take this opportunity to thank everyone who has used and supported CAPTCHA 4WP.</p>
<h3>A free and easy-to-use CAPTCHA plugin for WordPress</h3>
<p>Protect your WordPress forms and login pages from spam and automated attacks with <a href="https://captcha4wp.com/" rel="nofollow ugc">CAPTCHA 4WP</a>. Choose from multiple ReCAPTCHA versions and strike the right balance between security and user experience.</p>
<p><a href="https://captcha4wp.com/features/" rel="nofollow ugc">Features</a> | <a href="https://captcha4wp.com/pricing/" rel="nofollow ugc">Get the Premium!</a> | <a href="https://captcha4wp.com/docs/getting-started-with-captcha-4wp/" rel="nofollow ugc">Getting Started</a></p>
<p>Use the CAPTCHA 4WP plugin to add CAPTCHA checks to WordPress forms and logins. Choose from V2 (I’m not a robot), V2 Invisible, and V3 noCAPTCHA to ensure the best user experience at all times without compromosing security. Avoid false positives falling through the crack with V3 failover to ensure humans can still pass the test even if the result comes back below the passmark.</p>
<h3>CAPTCHA 4WP key plugin features and capabilities</h3>
<ul>
<li>Add CAPTCHA to WordPress native forms such as login pages, user registration and comments forms etc</li>
<li>Supports multiple ReCAPTCHA versions</li>
<li>User-friendly wizards for easy, hassle-free setup</li>
<li>Set ReCAPTCHA V3 passmark score </li>
<li>ReCAPTCHA failover configuration (ensure no prospect is incorrectly marked as spam)</li>
<li>Plugin automatically detects visitors’ language and shows CAPTCHA in that language</li>
<li>Much more</li>
</ul>
<h3>Upgrade to CAPTCHA 4WP Premium and get even more</h3>
<p>With the premium edition of CAPTCHA 4WP, you can choose from a wider range of CAPTCHA service providers, 1-click WooCommerce and other 3rd party plugin support, whitelisting, and much more.</p>
<h3>Premium features list</h3>
<ul>
<li>Everything in the free version</li>
<li>Add CAPTCHA from hCaptcha and Cloudflare Turnstile on your websites, both free and GDPR compliant</li>
<li>Add Geoblocking on forms and WordPress comments form (block / limit form submissions or comment posting by country)</li>
<li>Customization options for the CAPTCHA checks text, visual and position on the forms</li>
<li>One-click integration with WooCommerce</li>
<li>One-click integration with Contact Form 7, Gravity Forms, WPForms, BuddyPress & other plugins</li>
<li>Much more</li>
</ul>
<p>Refer to the <a href="https://captcha4wp.com/features/" rel="nofollow ugc">CAPTCHA 4WP plugin features and benefits page</a> to learn more about the benefits of upgrading to the Premium version of CAPTCHA 4WP.</p>
<h3>Free and premium support</h3>
<p>Support for CAPTCHA 4WP is free through the WordPress support forums.</p>
<p>Premium support for paid customer support is provided via one-to-one email. Upgrade to Premium to benefit from premium support.</p>
<p>For any other queries, feedback, or if you simply want to get in touch with us, please use our <a href="https://captcha4wp.com/submit-ticket/" rel="nofollow ugc">contact form</a>.</p>
<h3>As featured on:</h3>
<ul>
<li><a href="https://www.wpbeginner.com/plugins/how-to-add-captcha-in-wordpress-login-and-registration-form/" rel="nofollow ugc">WP Beginner</a></li>
<li><a href="https://www.elegantthemes.com/blog/wordpress/wordpress-captcha" rel="nofollow ugc">Elegant Themes</a></li>
<li><a href="https://www.isitwp.com/best-wordpress-captcha-plugins/" rel="nofollow ugc">IsItWP</a></li>
<li><a href="https://wplift.com/best-wordpress-captcha-plugins" rel="nofollow ugc">WPLift</a></li>
<li><a href="https://testerwp.com/best-free-captcha-wordpress-plugins/" rel="nofollow ugc">TesterWP</a></li>
</ul>
<h3>Related links and documentation:</h3>
<p>You can find more detailed information about CAPTCHA tests and the benefits you can take advantage of, and the plugin in the links below:</p>
<ul>
<li><a href="https://captcha4wp.com/why-need-captcha-wordpress-website/" rel="nofollow ugc">Why you need CAPTCHA on your WordPress website</a></li>
<li><a href="https://captcha4wp.com/different-types-captcha-checks-wordpress/" rel="nofollow ugc">The different types of CAPTCHA for websites</a></li>
<li><a href="https://captcha4wp.com/captcha-recaptcha-nocaptcha-differences/" rel="nofollow ugc">What is the difference between CAPTCHA, ReCAPTCHA, and NoCAPTCHA?</a></li>
<li><a href="https://captcha4wp.com/docs/getting-started-with-captcha-4wp/" rel="nofollow ugc">Getting started with CAPTCHA 4WP</a></li>
<li><a href="https://captcha4wp.com/docs/how-to-add-captcha-to-woocommerce-forms/" rel="nofollow ugc">How to add CAPTCHA on WooCommerce forms</a></li>
<li><a href="https://captcha4wp.com/docs/how-to-add-captcha-on-wpforms-forms/" rel="nofollow ugc">How to add CAPTCHA on WPForms</a></li>
<li><a href="https://captcha4wp.com/docs/how-to-add-captcha-on-gravity-forms-forms/" rel="nofollow ugc">How to add CAPTCHA on Gravity Forms</a></li>
<li><a href="https://captcha4wp.com/docs/how-to-show-captcha-on-failed-logins/" rel="nofollow ugc">How to show CAPTCHA on failed logins</a></li>
<li><a href="https://captcha4wp.com/" rel="nofollow ugc">Official Melapress website</a></li>
</ul>
<h3>Installing CAPTCHA 4WP</h3>
<h3>From within WordPress</h3>
<ol>
<li>Navigate to “Plugins”page and click the “Add New” button</li>
<li>Search for “CAPTCHA 4WP”</li>
<li>Cick install and after that activate the plugin</li>
</ol>
<h3>Manually</h3>
<ol>
<li>Download the plugin from the WordPress plugins repository</li>
<li>Unzip the zip file and upload the folder to the /wp-content/plugins/ directory</li>
<li>Activate CAPTCHA 4WP through the “Plugins” menu in WordPress</li>
</ol>


CAPTCHA 4WP – Antispam CAPTCHA solution for WordPress


For the past week, my site has been inundated with fake account registrations. Since adding this plugin yesterday there haven't been any new ones. I'm hopeful that it won't cause any problems for students signing up for my courses.


Yay no fake registrations today!


5 stars, no notes - MU/multisite support greatly appreciated


Perfect for me and MU support

Use CAPTCHA to stop spam and allow customers & users to interact with your website easily. Block fake accounts and orders. Avoid false positives.

Really Simple CAPTCHA vs CAPTCHA 4WP – Antispam CAPTCHA solution for WordPress