Takayuki Miyoshi

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.
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.
<h4>How does it work?</h4>
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.
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.
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.
<h4>How to use with your plugin</h4>
Note: Below are instructions for plugin developers.
First, create an instance of ReallySimpleCaptcha class:
<pre><code>$captcha_instance = new ReallySimpleCaptcha();
</code></pre>
You can change the instance variables as you wish.
<pre><code>// Change the background color of CAPTCHA image to black
$captcha_instance->bg = array( 0, 0, 0 );
</code></pre>
See really-simple-captcha.php if you are interested in other variables.
Generate a random word for CAPTCHA.
<pre><code>$word = $captcha_instance->generate_random_word();
</code></pre>
Generate an image file and a corresponding text file in the temporary directory.
<pre><code>$prefix = wp_rand();
$captcha_instance->generate_image( $prefix, $word );
</code></pre>
Then, show the image and get an answer from respondent.
Check the correctness of the answer.
<pre><code>$correct = $captcha_instance->check( $prefix, $the_answer_from_respondent );
</code></pre>
If the $correct is true, go ahead. Otherwise, block the respondent — as it would appear not to be human.
And last, remove the temporary image and text files, as they are no longer in use.
<pre><code>$captcha_instance->remove( $prefix );
</code></pre>
That’s all.
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>.

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.

hookandhook

Kyle Charlton

Add an SVG image captcha and honeypot to your Contact Form 7 or WPForms form. Based on our interpretation this CAPTCHA plugin is GDPR compliant because the images are inline SVGs and no download of external resources happens, in addition no cookies or other storing mechanisms are used on the user’s device, this plugin will not slow down your site with additional header requests like Google’s ReCAPTCHA and respects your users privacy.
<h4>Directions [PLEASE READ]</h4>
Contact Form 7: 
Add the shortcode [cf7ic] to the form editor where you want the CAPTCHA to appear.
You can hide the CAPTCHA until a user interacts with the form, by adding “toggle” to the shortcode: [cf7ic “toggle”]
WPForms: 
Just activate the CAPTCHA for WPForms on the plugin’s settings page.
Like the plugin? 
Please consider leaving a review.
As of version 3.2.0, Contact Form 7 Conditional Fields is now fully supported! You no longer need to add <code>[hidden kc_captcha "kc_human"]</code> to forms that do not include the [cf7ic] shortcode.
<h3>Go Pro!</h3>
Get even better spam protection with the All-in-one Image CAPTCHA Pro version of this plugin which includes additional options to improve spam protection, options to control the look and style of the CAPTCHA and messages, additional forms support including login screens, gravity forms, WooCommerce and more.
PRO Demo 
See the Pro version in action on my <a href="https://wpimagecaptcha.com/contact/?utm_source=wp_readme&utm_medium=wp_readme&wp_campaign=readme" rel="nofollow ugc">contact page</a>.
Check out our <a href="https://wpimagecaptcha.com/downloads/pro-plugin/?utm_source=wp_readme&utm_medium=wp_readme&wp_campaign=readme" rel="nofollow ugc">pro version</a> for more details.
PRO Features:
<ul>
<li>GDPR compliant</li>
<li>ADA/a11y/WCAG compliant</li>
<li>Gravity Forms support</li>
<li>WooCommerce support for login, registration and checkout forms (optional)</li>
<li>WordPress login/registration form support (optional)</li>
<li>Default WordPress comment support</li>
<li>Customize the look of the WordPress login/registration screen and form</li>
<li>CAPTCHA refreshes on submit to make it harder for automated spammers</li>
<li>Reverse honeypot which checks if you are human through form engagement</li>
<li>Stronger security with hashed answers to make it harder for automated spammers to read the answers</li>
<li>Add additional icons to increase the chances of a random guess getting through. You can increase it from a 1 and 3 chance all the way up to a 1 in 10 chance! </li>
<li>Select which icons you wish to use</li>
<li>Add additional icons from Font Awesome 4.7</li>
<li>Add your own custom SVG icons</li>
<li>Customize the icon titles</li>
<li>Change the captcha message</li>
<li>Change the captcha errors</li>
<li>Change the box color and border</li>
<li>Change font and icon color and size independently</li>
<li>Change the selected icon appearance</li>
<li>Change where the icons appear</li>
<li>Change the box from full width to content width</li>
<li>jQuery free on the front end</li>
</ul>
<a href="https://wpimagecaptcha.com/downloads/pro-plugin/?utm_source=wp_readme&utm_medium=wp_readme&wp_campaign=readme" rel="nofollow ugc">Go Pro!</a>

Image CAPTCHA for Contact Form 7 and WPForms by HookAndHook (DSGVO/GDPR)

All good, but today I've added some WPBakery Tabs block with buttons and have a lot of errors about not existing contact form when click the tab buttons. So I've fixed your script to enable captcha on form focus, now it really works only at CF7. Please replace your existing CF7 script function to my one:



function cf7ic_toggle()
{
 echo '<script type="text/javascript">
 document.addEventListener("focusin", cf7ic_display);

 function cf7ic_display(event){
 if(event.target.form && event.target.form.querySelector(".cf7ic-toggle")) {
 event.target.form.querySelector(".captcha-image").style.display = "block";
 }
 }

 document.addEventListener( "wpcf7mailsent", function( event ) {
 if (event.target.querySelector(".captcha-image")) {
 event.target.querySelector(".captcha-image").style.display = "none";
 document.activeElement.blur();
 }
 }, false );
 </script>';
}

JS needs to be fixed


Love the Plugin in its simplicity. The support is lightning fast!







Thanks So much


Great Support and Great Plugin

Adds an Image CAPTCHA to Contact Form 7 and WPForms, GDPR ready, perfect WPForms or Contact Form 7 Spam Protection Image CAPTCHA, adds a honeypot

Really Simple CAPTCHA vs Image CAPTCHA for Contact Form 7 and WPForms by HookAndHook (DSGVO/GDPR)