You can now use these API keys in the plugin settings on your WordPress website.
Adding reCAPTCHA to a WordPress Comment Form
Since you want to add the reCAPTCHA checkbox to your site, you need to select the first option, ‘I’m not a robot Checkbox’.
You can also use the Akismet plugin to automatically catch the most common types of spam comments by checking a global spam database. Akismet comes preinstalled with WordPress, but it is not activated by default.
First, you need to type your website name or any name of your choice in the ‘Label’ field. This will help you easily identify your site in the future.

You can also block spam comments using the Antispam Bee plugin. It lets you set rules about which users to trust, such as approved commenters or commenters with a Gravatar. You can also create rules that mark comments immediately as spam, such as when they contain code.
Once you have filled out the form, you can click on the ‘Submit’ button to register your site.
It is also super easy to set up and add to WordPress comment forms.
The plugin will ask you to provide Google reCAPTCHA API keys. You can create these keys for free from the official reCAPTCHA website by clicking the ‘register your domain’ link at the top of the screen.
Registering Your Website to Get reCAPTCHA API Keys
The ‘register your domain’ link will take you to the Google reCAPTCHA website, where you can register your site to work with reCAPTCHA.
We hope this tutorial helped you learn how to add reCAPTCHA to the WordPress comment form of your website. You may also want to see our guide on how to add reCAPTCHA to WordPress login and registration forms or our expert pick of the must-have plugins to grow your website.
In this tutorial, we will show you how to easily add reCAPTCHA to the comment form of your WordPress website.

What Is Google reCAPTCHA?
You can learn about these methods and many more in our expert pick of tips and tools to combat comment spam in WordPress.
On the settings page, you need to paste the site key and the secret key.

You can also add multiple domains or subdomains by clicking on the plus (+) icon. This will allow you to use the same API keys on different websites.

Google reCAPTCHA will now show you a success message along with the site key and the secret key on this page.

When you scroll down, you will see the ‘Domains’ textbox. This allows you to add the domain name of your website where you would like to add the reCAPTCHA checkbox.
To pass the test, users are required to click a checkbox indicating they are not a robot. They will either pass right away or be presented with a set of multiple images where they will need to click on matching objects.

Comment spam is a problem on many WordPress websites. Akismet, the popular spam filtering service for WordPress, blocks about 7.5 million spam comments every hour.
Now, you need to head back to the Advanced Google reCAPTCHA page in your WordPress admin area.
Note: The reCAPTCHA checkbox will be displayed only to logged-out users. To preview reCAPTCHA, you will need to either log out of WordPress or open your website in an Incognito window in your browser.