Pardot Forms Lead Capture

Overview

Pardot forms added to landing pages by default don't always work with the Metadata Lead Capture script, depending on how the forms have been configured.

Because Pardot forms are typically embedded in a cross-origin iframe, the Metadata script cannot directly detect form submissions. This guide provides two methods to resolve this, starting with the recommended approach.

Option 1 — Create a Form Handler (Recommended)

This is the recommended approach. Instead of using a Pardot iframe, you create a Form Handler in Pardot and embed a standard HTML form directly on your landing page. Because the form lives on the same page (not inside an iframe), the Metadata Lead Capture script can detect submissions automatically — no callback event or allowOrigin configuration needed.

1. Create a Form Handler in Pardot

1. Navigate to Marketing > Forms > Form Handlers
2. Click + Add Form Handler

2. Configure the basic settings

• Name your form handler
• Select a folder
• Choose a completion action (redirect URL, display thank you message, etc.)
• Configure success/error locations

3. Map Form Fields

In the "Form Field Mappings" section, add each field your HTML form will contain. For each field, specify:

• External field name — must exactly match the name attribute in your HTML form
• Pardot field — the Pardot field to map to
• Required — whether the field is required

4. Get the Endpoint URL

After saving, you'll receive a unique endpoint URL for your form handler.

5. Create Your HTML Form

Add a standard HTML form to your landing page that posts to the Form Handler endpoint:

<form action="YOUR_FORM_HANDLER_URL" method="post">
  <label for="email">Email</label>
  <input type="email" name="email" id="email" required>

  <label for="firstName">First Name</label>
  <input type="text" name="firstName" id="firstName">

  <label for="lastName">Last Name</label>
  <input type="text" name="lastName" id="lastName">

  <input type="submit" value="Submit">
</form>

That's it — the Metadata Lead Capture script will automatically detect and track submissions from this form.

Option 2 — Adding a Callback Event (Iframe Method)

Use this method if you need to keep the Pardot form embedded as an iframe. It requires two steps: adding a callback script in Pardot, and configuring allowOrigin in the Metadata script. Both steps are required — if either is missing, lead capture will silently fail.

1 : Add the Callback Script in Pardot

In the Pardot form builder, go to the Completion Actions tab and add the following script to the Thank You Content section:

Add this script:

<script type="text/javascript">
try {
  var postObject = JSON.stringify({
    event: 'ContactUsCallback',
    email: '%%email%%',
    firstname: '%%first_name%%',
    lastname: '%%last_name%%'
  });
  parent.postMessage(postObject, '*');
} catch(e) {
  window.console && window.console.log(e);
}
</script>

This script fires after the form is submitted and sends the lead data to the parent page via postMessage.

Important: Make sure the "Redirect to the following URL" checkbox is unchecked in the Completion Actions. If a redirect is enabled, the Thank You Content script will never execute and the callback will not fire.

2 : Configure allowOrigin in the Metadata Script

The Metadata Lead Capture script has the event listener built in, but it only accepts messages from origins listed in the allowOrigin configuration. You must add your Pardot domain to the init call.

Find the Metadata script initialization on your landing page and add the allowOrigin parameter:

Metadata.siteScript.init({
  accountId: 1234,
  allowOrigin: ["https://go.metadata.io"]
});

Replace https://go.metadata.io with your Pardot tracker domain — this is the origin of the iframe. It is typically a CNAME you have configured in Pardot, such as https://go.yourcompany.com or https://pages.yourcompany.com.

How to find your Pardot iframe origin

1. Open your landing page in a browser
2. Right-click the form area and select Inspect to open Developer Tools
3. Find the <iframe> element containing the Pardot form
4. Look at the src attribute — the origin is the protocol + domain portion
   (e.g., if the src is https://go.metadata.io/l/551262/2026-01-07/abc123, the origin is https://go.metadata.io)

Without allowOrigin, the Metadata script will silently ignore the postMessage from the Pardot iframe. There will be no error messages — lead capture will simply not work.

Troubleshooting

If you have set up the callback event (Option 2) but leads are still not being captured, check the following:

Still not working?

Contact support@metadata.io with:

• The URL of your landing page
• Your Pardot tracker domain (the iframe origin)
• A screenshot of your Metadata.siteScript.init() configuration