To save subscriber information that is entered on your website, you need to connect the Growtheme to ConvertKit. This involves typically two required steps and two optional steps. First you need to get your API Key and save it into the Growtheme Options. Second you need to specify a default form to use.

Then you can decide inside ConvertKit for each of your forms if you want to use a double or single opt-in process.

Additionally, if you use a double opt-in process you can set up convertkit to use the growtheme thank you page.

1. Get your API Key

Inside the Growtheme Options Panel » Email Provider click on the Convertkit Logo to show the convertkit Options.

Next you need to enter your personal convertkit API Key.

Click on the link below the Text field to get your convertkit API Key.

A new tab will open where you have to login with your convertkit username and password if you are not already logged in.

_images/convertkit-login.pngAfter login you should be automatically redirected to your Account Settings page If not go to it via clicking on your Account in the blue top navigation or just click here.

_images/convertkit-api-keys.pngYou will see a text field named “API Key” that contains your API Key. Copy it from the field.

_images/convertkit-api-key.pngGo back to the Growtheme Options Tab. Paste the copied API Key into the convertkit API Key text field.

Next click on Save Changes to connect the Growtheme to ConvertKit.

If you have copied and pasted the API Key correctly, you will see a success notice that the Growtheme is now connected to ConvertKit.

Additionally the convertkit API Status Field should indicate that you are successfully connected with convertkit.


If you haven’t created a Form inside ConvertKit yet, do this now. You can do this inside yourConvertkit Dashboard on the Forms Page or by clicking on this link.


2. Select a default Form to use

With Convertkit you can create an unlimited number of optin forms. This is great to differentiate between different optin forms and see which one works best. For example: You could use one convertkit form for the featurebox, one for the sidebar and one for a inside post optin box on a specific post.

But before you go ahead and create different forms for different optin boxes, you need to choose a default convertkit form. This is the form where your subscribers will be saved in by default. If you have just one form, it will already be selected.

You can choose this individually for every optin form later.


The Growtheme caches all requests to the Convertkit API. This speeds up your Growtheme Settings Panel and prevents that you have to wait every time you change something until the Convertkit Server responds. If you have made any changes inside your Convertkit Account that haven’t showed up within the Growtheme Settings Panel yet, you can use the Refresh Connection Button to delete all cached files and reset the connection.

3. Choose Single or Double Optin

With ConvertKit you have the option to choose between a Single Optin or Double Optin Process for each of your individual convertkit forms. If you decide to use Double Optin, visitors will have to confirm their email address before being subscribed to your ConvertKit list.


For some countries like Germany this is not an optional option, but required by law. Please review the specific laws of your own country regarding email marketing.


Using Double Optin usually results in a higher open rate, less spam reports and a general higher quality list. If you want to know more about this check out there Knowledge Base Article about the Double Optin Process.

You can easily enable or disable the double optin process inside ConvertKit for each individual form.

To disable double optin, go to your ConvertKit Dashboard » Forms (1) and choose a form you already created. Than choose the Settings (2) Tab and go to the Incentive Email (3) Section. Scroll down and select the checkbox Autoconfirm new subscribers (4).

_images/convertkit-use-single-optin.pngIf you decide to use a Single Optin Process, you are ready to go. The Growtheme will automatically redirect users to your custom Thank You Page after signing up. The Confirmation Page won’t be used in this case.

If you disable single optin on specific forms, the Growtheme will automatically notice and redirect subscribers to your confirmation page instead. If you are not using a downloadable incentive inside your convertkit form, you can redirect subscribers to your thank you page after clicking on the confirmation link (called Signup incentive or thank you page inside Convertkit).

4. Setup the Thank You Page


This is only required if you use a Double Optin Process for a specific Form and haven’t uploaded a Optin Incentive to ConvertKit

We have to setup ConvertKit to use our own custom Thank You Page. This Page will show up once a subscriber clicks on the confirmation link inside the confirmation email.

To do this, we first need the URL of our custom Thank You Page. Inside your WordPress Dashboard go to Growtheme » Customize.

Within the Wordpress Customizer go to the Thank You Page Section.

Next select and copy the Permalink of your Thank You Page.


You can switch the permalink of your Thank You page to anything you like, as long as it is a valid URL. Just remember that when you change the URL of your Thank You Page, you will have to update the Thank You Page URL within Convertkit as well.

Now go to ConvertKit. Inside the ConvertKit Dashboard go to Forms (1) and choose the Form you want to use the Growtheme Thank You Page with.

Then click on Settings (2) and select the Incentive Email (3) Section.


On this page you normally can configure as well the look and feel of your convertkit Signup Forms. As we are using the Growtheme to show our Signup Forms, you don’t need to change anything in particular on these signup form settings as these changes won’t take effect.


One thing you can and should configurate on this particular convertkit Page is the text of your Incentive email.

The Incentive email will be sended if you have Double Optin enabled as explained above and asks the visitor to confirm their email before they are subscribed to your list.

Paste the Thank You Page URL you have copied into the Signup incentive or thank you page (4) field and Save it.

_images/paste-thank-you-url.pngThis page will now show up once a subscriber clicks on the link inside the Incentive email.

You are now successfully connected to convertkit. Everything is set up. You can now go ahead and customize the Growtheme Options to your needs.