How to Connect OptinMonster with Marketo

OptinMonster offers seamless integration with Marketo email marketing service. Connecting OptinMonster to your Marketo email list is very easy.

In this article, you’ll learn how to connect Marketo with OptinMonster.

Before You Start

Here are some things to know before you begin:

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Connect Marketo

When you create a campaign in OptinMonster that you intend to collect leads with, you’ll want to integrate with one or more services to send those leads to.

To send leads to Marketo, follow these steps:

  1. Navigate to the Integrations tab and click Add New Integration.
  2. Search for and select Marketo from the dropdown field.
  3. Log into your Marketo account to obtain your API Key. To do this:
    1. In your Marketo account create a custom service.
    2. Once you have a custom service you will need to locate your Client ID and Client Secret.
      Navigate to the Admin page.
      Select the Admin link from your Marketo account.
    3. Next, select LaunchPoint from the Integration section.
      Select Launchpoint from the Marketo Integrations screen
    4. Your custom services will be listed, select View Details on the custom service you’ve created for OptinMonster.
      View Details of your Marketo integration
    5. Copy the Client ID and Client Secret from the lightbox.
      Copy API Details from Marketo for OptinMonster
  4. Returning to the OptinMonster campaign builder, paste your Client ID  and Client Secret into the corresponding fields.
    Enter the Marketo API details into each corresponding field in OptinMonster.
  5. Copy the Marketo Subdomain from the REST API page of your Marketo account and paste it into the corresponding field in the OptinMonster campaign builder.
       Note: you only need to copy the first portion of the subdomain, do not include the beginning https:// or ending Adding the full subdomain url will prevent OptinMonster from connecting to your Marketo account.
    Marketo Sub-domain
  6. Next, select the Connect to Marketo button.
    Connect to Marketo
  7. Once connected, select the Partition you wish to use.
    Marketo Partition
  8. Finally, select the List you would like to add leads to.
    Marketo Lists
  9. When you’re finished, click Save.

Email Automations

To send emails automatically to new leads you’ll want to configure email automations within your Marketo account.

The following guides from Marketo may be helpful to get started:


I’ve connected my integration and new leads are being added to my list, but OptinMonster shows 0 conversions for my campaign. Why?

Confirm that conversion tracking is turned on for the submit button in your campaign. See our guide on How to Enable Conversion Tracking.

What if my Marketo plan doesn’t include API Integrations?

Some Marketo plans don’t allow you to use the Marketo API to add subscribers to your account.

However, you can still use our Custom HTML Optin Form integration option to add subscribers to your Marketo account without using their API.

Can OptinMonster send Lead Scoring Data to Marketo’s Munchkin platform?

Yes, OptinMonster works with Marketo’s Munchkin platform and you can pass along Lead Scoring Data to it.

Is it possible for me to add a Phone Field to my campaign?

Yes! You can add a phone field. Check out How to Capture Phone Numbers with OptinMonster here.