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Add a captcha to your subscription form

We strongly recommend using a captcha (reCAPTCHA) confirmation to prevent spambots from adding fake data to your lists. 

In this tutorial, we will show you how you can create a reCaptcha on Google and then add reCaptcha to your Sendinblue form.

Create your reCaptcha on Google

  1. Go to and log into your Google account.
  2. Add a Label to your form.
  3. Select reCAPTCHA v2.
    Note: reCAPTCHA v3 is not supported in Sendinblue.
  4. Choose the type of reCaptcha you need
  5. You will fill the Domains field according to the way you will share your form (Form > step 6 Share).
    • If you want to share your form using Quick Share or Iframe: add the domain It is the domain Sendinblue uses to host the form.
    • If you want to integrate your form with HTML or Simple HTML: add the domain of the website where you will display the form. Example: If you will add the form on, you would add in this field.
      Note: If you're not sure how you will share the form, you can add both the above domains.
  6. (Optional) Add other Owners if needed. Owners will have ownership rights over the site key. Each email address must be associated with a Google account.
  7. Accept the reCAPTCHA Terms of Service.
  8. Click Submit.

Your reCaptcha is created! You will now see a page displaying the Site Key and Secret Key. You will use these keys in the following step to configure reCaptcha within the form.

💡 Good to know
The site key and secret key can be used across multiple forms. 

Add reCaptcha to your Sendinblue form

  1. Drag and drop the Captcha block in your form.
  2. Copy and paste the Site Key and Secret Key from the previous procedure in their respective fields.
  3. Select Label to add a label to your reCaptcha.
  4. Select Help Text to add a caption below your reCaptcha.
  5. Select Invisible Captcha only if you have chosen "Invisible reCaptcha badge" when you created your reCaptcha on Google.


You may receive these error messages once you share the form :


  • Invalid domain for site key: please check your domain field.
  • Invalid key type: if you select reCAPTCHA v3, you may receive this error message on your form. Only reCAPTCHA v2 is supported. 

⏩ What's next?

🤔 Have a question?

If you have a question, feel free to contact our support team by creating a ticket from your account. If you don't have an account yet, you can contact us here.