scolar

As of version 3 of the reCaptcha, adding this functionality to your website makes the logo of Google appear on all pages of your website. 
The plugin loads 2.5 seconds after the page has loaded. This is because we need to give Contactform 7 time to show its form.
The plugin will work on most WordPress installations, there’s hardly any php code, so hardly any server requirements. 
At this point in time it does require jQuery, which is handled automatically.

ScolaCaptcha

This plugin hides the Google reCaptcha Version 3 logo on all pages except the pages that contain a Contactform 7 form.

teamzt

The ZT Captcha plugin is a robust security tool for WordPress websites, offering a range of features that allow administrators to customize the captcha functionality. Here are the key features:
1. Form Integration: Administrators can enable or disable the captcha on various default WordPress forms such as:
<ul>
<li>Login form.</li>
<li>Registration form.</li>
<li>Reset password form.</li>
<li>Comment form.</li>
</ul>
2. Captcha Types: Administrators can select different types of captchas:
<ul>
<li>Numeric captcha.</li>
<li>Alphabetic captcha.</li>
<li>Mathematical captcha with random option.</li>
<li>Mathematical captcha with algebraic operations.</li>
</ul>
3. Captcha Customization: Administrators can customize the captcha string by:
<ul>
<li>Including special characters.</li>
<li>Including uppercase letters.</li>
<li>Setting a limit on the number of captcha digits.</li>
</ul>
This plugin is designed to enhance the security of WordPress websites by implementing a human verification test to protect against potential spam and unauthorized access attempts.

ZT Captcha

The captcha plugin keeps WordPress sites safe from spam and password hacks by requiring a simple test to prove you're human, not a computer.

ScolaCaptcha vs ZT Captcha