f13dev

Add Google reCaptcha to the comments section on blog posts. Requires Google reCaptcha v2 Checkbox API key.
Simple configuration via the admin settings page: 
* reCaptcha public key 
* reCaptcha private key 
* enable reCaptcha for (Everyone | Visitors | Nobody [disabled])
Additional hooks for programmers: 
$v = apply_filters(‘f13_recaptcha_add’); 
Will place a reCaptcha checkbox in the desired place.
$validate = apply_filters(‘f13_recaptcha_validate’); 
if (!empty($validate)) { 
 $v = $validate 
 // reCaptcha failed 
} else { 
 // reCaptcah passed 
}

F13 reCaptcha

Add Google reCaptcha to the comments section on blog posts. Additional hooks for adding reCaptcha to custom forms.

Mukul Hossain

Add an text captcha to your contact form 7 form. 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>
Add the shortcode [cf7tc] to the form editor where you want the captcha to appear.
Like the plugin? 
Please consider leaving a review.
Demo
Check out <a href="https://getwebexperts.com/contact-form-7-text-captcha" rel="nofollow ugc">demo</a>

F13 reCaptcha vs Text Captcha For Contact Form 7 [GWE]