Formidable Forms + Meta Ads Conversion Tracking Setup

I see this exact combo broken in about 30% of WordPress accounts I audit. The problem is almost always the same: Formidable Forms fires its frmFormComplete event, but it’s not being captured properly by the Meta Pixel, or worse — it’s firing duplicate events when someone uses both client-side pixel and CAPI without proper deduplication. Your Meta Ads data becomes garbage, and you’re optimizing campaigns toward phantom conversions.

What You’ll Have Working By The End

Prerequisites

Step 1: Set Up the Formidable Forms Event Listener

Formidable Forms fires a frmFormComplete event when someone submits a form, but by default it doesn’t push anything to the data layer. Add this code to your theme’s functions.php or in a custom plugin:

add_action('frm_after_create_entry', 'push_formidable_to_datalayer', 30, 2);

function push_formidable_to_datalayer($entry_id, $form_id) {
    // Get the form and entry details
    $form = FrmForm::getOne($form_id);
    $entry = FrmEntry::getOne($entry_id);
    
    // Get field values (customize based on your form fields)
    $email = FrmEntryMeta::get_entry_meta_by_field($entry_id, 'email');
    $first_name = FrmEntryMeta::get_entry_meta_by_field($entry_id, 'first_name');
    $last_name = FrmEntryMeta::get_entry_meta_by_field($entry_id, 'last_name');
    
    // Generate unique event ID for deduplication
    $event_id = 'frm_' . $form_id . '_' . $entry_id . '_' . time();
    
    ?>
    <script>
        window.dataLayer = window.dataLayer || [];
        window.dataLayer.push({
            'event': 'formidable_form_submit',
            'form_id': '<?php echo $form_id; ?>',
            'form_title': '<?php echo esc_js($form->name); ?>',
            'entry_id': '<?php echo $entry_id; ?>',
            'event_id': '<?php echo $event_id; ?>',
            'user_data': {
                'email': '<?php echo esc_js($email); ?>',
                'first_name': '<?php echo esc_js($first_name); ?>',
                'last_name': '<?php echo esc_js($last_name); ?>'
            }
        });
    </script>
    <?php
}

Important: Replace 'email', 'first_name', 'last_name' with your actual Formidable Forms field keys. You can find these in your form builder under each field’s advanced settings.

Step 2: Create the GTM Trigger

In Google Tag Manager:

  1. Go to Triggers → New
  2. Choose Custom Event trigger type
  3. Set Event name to: formidable_form_submit
  4. Leave This trigger fires on set to “All Custom Events”
  5. Name it: “Formidable Forms - Form Submit”
  6. Save

If you want to track specific forms only, add this condition:

Step 3: Configure the Meta Pixel Event Tag

Create a new tag in GTM:

  1. Tag Type: Meta Pixel

  2. Event Name: Lead (or use a custom conversion name)

  3. Meta Pixel ID: Your pixel ID

  4. Event Parameters:

    content_name: {{DLV - form_title}}
content_category: form_submission
value: 1
currency: USD

  5. Advanced Settings → Ecommerce Settings:

    • event_id: {{DLV - event_id}}
    • user_data: 
      {
  "email": "{{DLV - user_data.email}}",
  "first_name": "{{DLV - user_data.first_name}}",
  "last_name": "{{DLV - user_data.last_name}}"
}

  6. Triggering: Select your “Formidable Forms - Form Submit” trigger

  7. Save and name it “Meta Pixel - Formidable Forms Lead”

Which event name should you use? If this is a contact form or newsletter signup, use “Lead”. If it’s a purchase form or high-intent action, create a custom conversion in Meta Events Manager first, then use that custom event name instead.

Step 4: Set Up Meta CAPI for Server-Side Tracking

Client-side pixels get blocked by about 20% of users. CAPI ensures you capture more conversions. Add this to your Formidable Forms webhook or the same function from Step 1:

function send_formidable_to_meta_capi($entry_id, $form_id) {
    $access_token = 'your_capi_access_token';
    $pixel_id = 'your_pixel_id';
    
    // Get entry data
    $entry = FrmEntry::getOne($entry_id);
    $email = FrmEntryMeta::get_entry_meta_by_field($entry_id, 'email');
    $first_name = FrmEntryMeta::get_entry_meta_by_field($entry_id, 'first_name');
    $last_name = FrmEntryMeta::get_entry_meta_by_field($entry_id, 'last_name');
    
    // Same event ID as client-side for deduplication
    $event_id = 'frm_' . $form_id . '_' . $entry_id . '_' . time();
    
    $data = array(
        'data' => array(
            array(
                'event_name' => 'Lead',
                'event_time' => time(),
                'event_id' => $event_id,
                'action_source' => 'website',
                'event_source_url' => home_url($_SERVER['REQUEST_URI']),
                'user_data' => array(
                    'email' => array(hash('sha256', strtolower(trim($email)))),
                    'first_name' => array(hash('sha256', strtolower(trim($first_name)))),
                    'last_name' => array(hash('sha256', strtolower(trim($last_name)))),
                    'client_ip_address' => $_SERVER['REMOTE_ADDR'],
                    'client_user_agent' => $_SERVER['HTTP_USER_AGENT']
                ),
                'custom_data' => array(
                    'content_name' => 'Formidable Form ' . $form_id,
                    'value' => 1,
                    'currency' => 'USD'
                )
            )
        )
    );
    
    $url = "https://graph.facebook.com/v18.0/{$pixel_id}/events?access_token={$access_token}";
    
    wp_remote_post($url, array(
        'body' => json_encode($data),
        'headers' => array('Content-Type' => 'application/json')
    ));
}

// Add this to your existing hook
add_action('frm_after_create_entry', 'send_formidable_to_meta_capi', 35, 2);

Get your CAPI access token: Go to Meta Events Manager → Settings → Conversions API → Generate Access Token.

Step 5: Create Data Layer Variables in GTM

You need these variables to capture the data from your form submissions:

  1. DLV - form_title:

    • Variable Type: Data Layer Variable
    • Data Layer Variable Name: form_title

  2. DLV - event_id:

    • Variable Type: Data Layer Variable
    • Data Layer Variable Name: event_id

  3. DLV - user_data.email:

    • Variable Type: Data Layer Variable
    • Data Layer Variable Name: user_data.email

Repeat for first_name and last_name. You’ll reference these in your Meta Pixel tag configuration.

Testing & Verification

In Meta Events Manager

  1. Go to Events Manager → Test Events
  2. Enter your website URL
  3. Submit a test form on your site
  4. You should see both:
    • Browser event (from pixel)
    • Server event (from CAPI)
    • Both should have the same event_id for proper deduplication

Check the Raw Data

  1. In Events Manager, click on your pixel
  2. Go to Activity tab
  3. Look for your Lead events with:
    • content_name: Your form title
    • event_id: The generated ID
    • event_source_url: The page where the form was submitted

Cross-Reference Numbers

If your Meta count is more than 20% higher than Formidable entries, you likely have a deduplication problem.

Troubleshooting

Problem: Events showing in Test Events but not in regular Events Manager activity → Check that your Meta Pixel ID matches between GTM tag and CAPI code. Also verify your access token has the correct permissions.

Problem: Double-counting conversions (Meta count much higher than actual form submissions) → Your event_id isn’t matching between pixel and CAPI. Make sure both are using the exact same ID format and timing.

Problem: CAPI events not showing up at all → Most likely a server configuration issue. Check that wp_remote_post is working by adding error logging. Some hosts block external API calls.

Problem: Form submissions trigger multiple Meta events → This happens when Formidable’s AJAX submission fires the event, then the page redirects and fires it again. Add a check in your PHP code to only fire once per entry ID.

Problem: User data not populating in Meta for audience building → Verify your Formidable field keys match what you’re using in the code. Check the actual field names in your form builder — they’re often different from the display labels.

Problem: Events firing for form spam/bot submissions → Add Formidable’s built-in spam detection check: if (!FrmEntryValidate::validate($values)) { return; } before sending to Meta.

What To Do Next

This guide is part of the Meta Ads Conversion Tracking hub — complete setup guides for tracking any conversion source in Meta Ads.