Have you been searching for a simple yet effective opt-in feature for your WordPress form? Look no further than Ninja Forms. With its user-friendly interface and extensive features, creating and customizing WordPress opt-in forms is a breeze.

Opt-in forms act as the digital doormen of the online world, inviting visitors to willingly step into the realm of email communication. With a simple click, users express their interest and consent to receive updates, educational materials, promotions, newsletters, and more. Whether through a subtle invitation or promises of exclusive content, businesses can incentivize sign-ups and lay the foundation for meaningful interactions.

There are two types of opt-in methods: single opt-in and double opt-in.

Table of Contents

1. Install Ninja Forms
2. Integrate Ninja Forms with email marketing software
3. Create the WordPress single opt-in form
4. Ninja Forms and Mailchimp double opt-in settings
5. Choosing the best opt-in for your WordPress form

How to add an opt-in with Ninja Forms

Step 1: Install Ninja Forms

Begin by installing the free Ninja Forms plugin on your WordPress site. You can find it in:

• The Ninja Forms website (Ninja Forms core plugin (download)
• Your WordPress website.

Step 2: Integrate Ninja Forms with email marketing software

For this guideline, we’ll seamlessly connect our opt-in form with Mailchimp email marketing software. Thanks to Ninja Forms’ Mailchimp add-on, this integration requires no custom coding or complex actions to set up.

Step 3: Create the WordPress single opt-in form

Single opt-in

Single opt-in is a subscription method for email and SMS marketing that allows users to subscribe in one simple step to start receiving messages.

Process:

• A user provides their email address on a sign-up form.
• The email address is immediately added to the mailing list.
• The user starts receiving emails right away.

Pros:

• Quick and easy for the user, reducing barriers to subscription.
• Faster list growth, as there is no additional step for the user to confirm their subscription.

Cons:

• Higher risk of fake or mistyped email addresses, which can lead to higher bounce rates.
• Increased likelihood of spam complaints if users forget they signed up.
• Potential for lower engagement rates because users may not be as committed.

Create a new form with all the fields that you require. For this guideline, let’s create a WordPress opt-in form with First Name, Email, and the Mailchimp opt-in fields.

You’ll have the option to add the Mailchimp opt-in field once you have installed the Mailchimp add-on. 

1. Click “Add new field”, scroll to Common Fields, and click “Mailchimp opt-in.”

2. Label the field “Subscribe to Our Newsletter” and set the Default Value option to “Unchecked.” This empowers users with the choice to opt-in by checking the box.

3. Go to “Emails & Actions” tab to add the Mailchimp action. This email action becomes accessible upon installation of the Mailchimp add-on.  

4. Map the fields. This process allows the form fields to connect with the corresponding Mailchimp fields, ensuring smooth information exchange. Before you begin, ensure that you have created the Mailchimp list and all the necessary fields.

1. • Select the list to which you want to send the data—in our case, the list is called Newsletter. 
   • Map the fields accordingly. We have linked the Email and First Name fields to their respective counterparts in Mailchimp. 
   • Make sure you save all those changes. 

Your WordPress form is now ready for a single opt-in.

Step 4: Ninja Forms and Mailchimp double opt-in settings

Double opt-in

The double opt-in subscription method requires users to subscribe and then confirm their email by clicking a link sent to them.

Process:

• A user provides their email address on a sign-up form.
• An email is sent to the provided address with a confirmation link.
• The user must click the confirmation link to verify their email address.
• After the user confirms, the email address is added to the mailing list.

Pros:

• Ensures email addresses are valid and active, reducing bounce rates.
• Subscribers are more likely to be genuinely interested, leading to higher engagement rates.
• Lower risk of spam complaints because users explicitly confirm their intention to subscribe.

Cons:

• The additional step may discourage some users from completing the subscription, leading to slower list growth.
• Confirmation emails may end up in spam folders, causing some users to miss them and not complete the opt-in process.

For double opt-in, start by completing the single opt-in steps, then add the following settings:

1. 1. Within the Mailchimp Action settings, navigate to the Advanced section and toggle on the option to Require Subscribers to Confirm Their Subscription
   2. To enable double opt-in on Mailchimp, go to Audience and click Manage Audience > Settings > Audience name and campaign defaults.
   3. Select the option to enable double opt-in.

Your double opt-in is fully activated and ready to go.

Learn how to style your Ninja Forms to make them visually stunning and engaging.

If you use an email marketing software other than Mailchimp, we’ve got you covered. Here’s a list of alternative email marketing platforms that Ninja Forms can integrate with: ConvertKit, AWeber, ActiveCampaign, Constant Contact, CleverReach, Campaign Monitor, MailPoet, Emma, and EmailOctopus. For other email marketing software integrations with Ninja Forms, use Zapier.

Which opt-in is best for your WordPress form?

Choosing between single and double opt-in depends on your specific goals and priorities for your email marketing campaign.

Single opt-in is typically used when rapid list growth is a priority and the quality of email addresses is less of a concern. It’s suitable for scenarios where ease of subscription is essential.

Double opt-in is preferred when the quality and engagement of subscribers are more important than the quantity. It’s ideal for building a highly engaged audience and reducing issues with spam and invalid email addresses.

And did you know…

Did you know the Ninja Forms core plugin is free? It comes packed with a bunch of awesome features, like calculations, unlimited submissions, submission management, spam protection, and more. Check out all the features that come included for free in the Ninja Forms core plugin!

Besides our free features, we offer over 40 different integrations to help match your needs and wants into a form-building experience unlike any other. Unlike our competitors, all our add-ons can be purchased individually in one-, five-, or twenty-site licenses. Need more add-ons? We recommend going with one of our membership plans, including additional discounts for even more add-ons!

Want to learn more about Ninja Forms? Check out our frequently asked questions to get your answers right away!