How to Capture UTM Parameters in Gravity Forms (Works with WP Engine Caching)

Tracking where your form submissions come from is critical for understanding campaign performance. If you’re using Gravity Forms on a cached WordPress site (especially on hosts like WP Engine), capturing UTM parameters can be trickier than it looks.

This guide walks through a reliable, cache-safe method to capture UTM parameters in Gravity Forms that works for logged-in and logged-out visitors.

What Are UTM Parameters?

UTM parameters are query string values added to URLs to track marketing attribution. Common examples include:

utm_source=email
utm_medium=cpc
utm_campaign=summer_promo
utm_term=donations
utm_content=cta_button

When someone submits a form, storing these values allows you to see:

• which channel drove the conversion
• which campaign performed best
• which messaging worked

Why Gravity Forms UTM Tracking Fails on Cached Sites

Gravity Forms has a built-in feature called Dynamic Population, which lets you map URL parameters directly into form fields.

This works only when pages are not cached.

On platforms like WP Engine:

• Logged-out visitors are served cached HTML
• The server never re-renders the page per URL
• ?utm_* values are ignored
• Forms appear empty even though UTMs are present in the link

This leads to a confusing situation:

• ✅ Works when logged in
• ❌ Fails in incognito / logged out

To solve this properly, UTMs must be captured client-side using JavaScript.

The Correct Way to Capture UTM Parameters in Gravity Forms

The reliable solution is:

1. Read UTM parameters from the browser URL
2. Store them in cookies (optional but recommended)
3. Inject them into Gravity Forms hidden fields using JavaScript
4. Wait until Gravity Forms is fully rendered (important for AJAX forms)
5. Support multiple forms if needed

This approach works:

• with WP Engine caching
• with AJAX-enabled forms
• for logged-out visitors
• across multiple pages or steps

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Step-by-Step Guide to Capture UTM Parameters in Gravity Forms

Step 1: Add hidden fields to your Gravity Form

In the Gravity Forms editor, add Hidden fields for each UTM you want to capture:

• utm_source
• utm_medium
• utm_campaign
• utm_term
• utm_content

After adding each field:

• Save the form
• Inspect the page to note the generated input IDs

Gravity Forms inputs follow this format:

input_{FORM_ID}_{FIELD_ID}

Example:

input_103_41

Where:

• 103 = Form ID
• 41 = Field ID

You will need these IDs for the script.

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Step 2: Use this JavaScript snippet (cache-safe)

This script:

• captures UTMs from the URL
• falls back to cookies if the user navigates
• fills Gravity Forms hidden fields
• works with cached pages
• supports multiple forms

Example script

<script>
(function () {

  var forms = [
    {
      formId: 103,
      map: {
        utm_source: 41,
        utm_medium: 42,
        utm_campaign: 43,
        utm_term: 44,
        utm_content: 45
      }
    },
    {
      formId: 104,
      map: {
        utm_source: 49,
        utm_medium: 51,
        utm_campaign: 52,
        utm_term: 50,
        utm_content: 53
      }
    }
  ];

  function getQueryParam(name) {
    return new URLSearchParams(window.location.search).get(name) || '';
  }

  function setCookie(name, value, days) {
    if (!value) return;
    var d = new Date();
    d.setTime(d.getTime() + (days * 24 * 60 * 60 * 1000));
    document.cookie = name + '=' + encodeURIComponent(value) +
      '; expires=' + d.toUTCString() + '; path=/; SameSite=Lax';
  }

  function getCookie(name) {
    var match = document.cookie.match(
      new RegExp('(?:^|; )' + name.replace(/([.$?*|{}()[\]\\/+^])/g, '\\$1') + '=([^;]*)')
    );
    return match ? decodeURIComponent(match[1]) : '';
  }

  function fillForm(config) {
    Object.keys(config.map).forEach(function (key) {
      var value = getQueryParam(key) || getCookie('kyra_' + key);
      if (!value) return;

      setCookie('kyra_' + key, value, 30);

      var input = document.getElementById('input_' + config.formId + '_' + config.map[key]);
      if (input) input.value = value;
    });
  }

  function waitAndFill() {
    var tries = 0;
    var maxTries = 60;

    var timer = setInterval(function () {
      tries++;

      forms.forEach(function (cfg) {
        var exists = Object.values(cfg.map).some(function (id) {
          return document.getElementById('input_' + cfg.formId + '_' + id);
        });
        if (exists) fillForm(cfg);
      });

      if (tries >= maxTries) clearInterval(timer);
    }, 200);
  }

  document.addEventListener('DOMContentLoaded', waitAndFill);
  document.addEventListener('gform_post_render', waitAndFill);

})();
</script>

Step 3: Where to place the script

Recommended options:

• WPCode → HTML Snippet → Site Wide Footer
• Child theme footer.php
• Google Tag Manager (Custom HTML tag)

Avoid placing this inside page content if your site uses aggressive caching or optimization.

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Important Notes for WP Engine Users

Always ensure your campaign links include the trailing slash if your site redirects URLs.

Correct:

/landing-page/?utm_source=google

Incorrect:

/landing-page?utm_source=google

Some redirect rules drop query parameters if the slash is missing.

How to Test Gravity Forms UTM Tracking

1. Open an incognito window
2. Visit the page with UTMs: ?utm_source=test&utm_medium=test
3. Submit the form
4. Check the Gravity Forms entry
5. Confirm all UTM fields are populated

Can This Be Extended to Click IDs?

This setup can easily be extended later to capture:

• gclid (Google Ads)
• msclkid (Microsoft Ads)
• fbclid (Meta)

You simply:

1. Add hidden fields
2. Add them to the map object
3. No logic changes required

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Final Thoughts

If you’re running Gravity Forms on a cached WordPress host, client-side UTM capture is the only reliable method.

This approach:

• avoids cache issues
• works for logged-out visitors
• supports multiple forms
• is easy to maintain and extend

If you need help implementing this on your site or adapting it to CRMs like HubSpot, Salesforce, or Dynamics, this pattern scales cleanly. If you need help with implementation, please get in touch with our expert team. Click here