wppal

Easy Captcha is an ideal solution for those who want to try different types of captcha to achieve an optimal site usability and captcha protection ratio. It allows a WordPress site owner to choose which captcha should be used on a particular page.
Currently the plugin supports 3 types of captcha:
<ul>
<li>Hidden captcha, </li>
<li>Simple image captcha,</li>
<li>Google reCaptcha</li>
</ul>
Hidden Captcha is invisible to site visitors and does not assume any specific user actions. It just checks that a visitor behaves like a human. Although it might seem that Hidden Captcha does not fully correspond to the definition of CAPTCHA (found at the end of the FAQ), it still distinguishes a human from a bot based on natural human behavior. Hidden Captcha also allows checking whether a visitor’s browser has JavaScript and Cookies enabled.
Simple Captcha works in a traditional manner: it shows an image and requires a user to enter a captcha code. Simple Captcha stores captcha values on the server side using a custom session approach.
reCaptcha is a reliable and powerful captcha service provided by Google for free. Please visit <a href="http://google.com/recaptcha" rel="nofollow ugc">reCaptcha site</a> for more details
Any type of captcha from above may be added to the following WordPress site places:
<ul>
<li>Comment forms,</li>
<li>Login page,</li>
<li>Registration page,</li>
<li>Password reset page. </li>
</ul>
With Easy Captcha you can easily install different types of captcha on each individual page.
Please read the FAQ and Installation sections for more details.

Easy Captcha

Several types of captcha to protect your site in one easy to use plugin.

jmviade

reCAPTCHA in WP comments form plugin is an ANTISPAM tool that adds the visible Google reCAPTCHA field inside the comments form of your WP theme when the user is not logged in preventing fraudulent or deceptive comments.
The plugin also introduces a second verification process that detects the unauthorized direct accesses by spam robots to the WP comments system and allows you to decide what do you want to do with those comments.
Finally, the plugin has got an optional forced javascript output mode that lets you to add a reCAPTCHA field also in old WP themes that didn’t use the new WP form comments functions but they make a direct output of its own comments form.
<h4>FEATURES LIST</h4>
Basic Features
<ul>
<li>All variants of Google reCAPTCHA field are available</li>
<li>Two simple steps Installation Wizard</li>
<li>Automatic default configuration settings for all plugin components</li>
<li>Automatic default configuration for reCAPTCHA field</li>
<li>Configuration settings for Plugin </li>
<li>Configuration settings for ANTISPAM operation</li>
<li>Four modes of operation in case of spam robots threats (SPAM, TRASH, DELETE or DIE)</li>
<li>Visual configuration settings for Google reCAPTCHA: theme, size, type, align, language</li>
<li>Dynamic comments form sample for viewing configuration settings changes</li>
<li>Visual Help</li>
<li>RTL Language support</li>
<li>Admin Color scheme adapted</li>
</ul>
Middle features
<ul>
<li>Forced language option for reCAPTCHA field</li>
<li>Plugin blocks the submit button while reCAPTCHA field is not verified</li>
<li>Plugin changes HTML structure of the comments form to prevent malicious automatic sendings while reCAPTCHA field is not verified</li>
<li>Plugin also blocks other elements with <code>[type=submit]</code> inside form in case of a theme customized comments form</li>
<li>Plugin lets you to write your own additional CSS for the reCAPTCHA field</li>
<li>New restore default value buttons in plugin configuration section for helping you in case of changing WP theme, accidental errors, test environtments, etc.</li>
</ul>
Advanced features
<ul>
<li>reCAPTCHA verification process via AJAX before submitting the form</li>
<li>Second security checking process for preventing any security breach before saving the comment</li>
<li>Supporting four different WP comments form HTML structure types</li>
<li>Advanced plugin options based on HTML queries for inserting the reCAPTCHA plugin in all kinds of WP themes</li>
<li>Optional Forced javascript output that allows you to use the plugin with old WP themes that didn’t use function <code>comment_form()</code></li>
<li>Advanced ID’s tags settings for using this plugin with WP Themes that creates its own comments form HTML struct</li>
<li>reCAPTCHA javascript initialization that prevents reCAPTCHA conflicts in case of that other plugins use reCAPTCHA.</li>
<li>New mínimum CSS styles for recaptcha alignment</li>
</ul>
<h4>PLUGIN PAGE</h4>
To learn more about the plugin, visit the <a href="http://www.joanmiquelviade.com/plugin/google-recaptcha-in-wp-comments-form/" title="Author's plugin page" rel="nofollow ugc">Plugin page</a>.

reCAPTCHA in WP comments form

reCAPTCHA in WP comments form is an ANTISPAM tool that adds a Google reCAPTCHA to the comments form and protects your site from the spam robots threat …

Easy Captcha vs reCAPTCHA in WP comments form