Install Google Tag Manager on Concrete CMS

How to install GTM on Concrete CMS (formerly Concrete5) using Header/Footer blocks, page templates, or theme customization.

Google Tag Manager (GTM) is the recommended method for managing analytics and marketing tags on Concrete CMS. This guide covers installation methods, best practices, and Concrete CMS-specific considerations.

Why Use GTM on Concrete CMS?

Benefits:

Manage all tags from one interface (GA4, Meta Pixel, etc.)
No code changes required after initial installation
Better performance (single container vs multiple scripts)
Easier for marketers to update without developer help
Built-in debugging and preview tools
Version control and workspace management

Concrete CMS-Specific Advantages:

Works across all page types and templates
Easy integration with form submissions
Can exclude edit mode and dashboard pages
Compatible with marketplace add-ons
Survives theme updates when properly implemented

Installation Methods

Method	Difficulty	Flexibility	Updates	Recommended
Header/Footer Block	Easy	Low	Dashboard	Best for most sites ✓
Page Template	Medium	Medium	File editing	Custom themes
Theme Customization	Advanced	High	File editing	Developers

Method 1: Header/Footer Block (Recommended)

The simplest method using Concrete CMS's built-in tracking code functionality.

Step 1: Create GTM Account and Container

Go to Google Tag Manager
Create Account
- Account Name: Your company name
- Country: Your location
Create Container
- Container Name: Your website domain (e.g., example.com)
- Target Platform: Web
Accept Terms of Service
Copy Container Code

You'll see two code snippets:
- Head snippet: Goes in <head>
- Body snippet: Goes in <body>
Your Container ID will look like: GTM-XXXXXXX

Step 2: Add GTM via Dashboard

Concrete CMS v9+:

Access Tracking Codes
- Log in to Dashboard
- Go to System & Settings → SEO & Statistics → Tracking Codes

Add GTM Head Code

In the "Tracking Code (Header)" field, add:

<!-- Google Tag Manager -->
<script>(function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':
new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],
j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src=
'https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);
})(window,document,'script','dataLayer','GTM-XXXXXXX');</script>
<!-- End Google Tag Manager -->

Replace GTM-XXXXXXX with your actual Container ID.

Add GTM Body Code

If your version supports "Tracking Code (Body)" or "Additional Scripts", add:

<!-- Google Tag Manager (noscript) -->
<noscript><iframe src="https://www.googletagmanager.com/ns.html?id=GTM-XXXXXXX"
height="0" width="0" style="display:none;visibility:hidden"></iframe></noscript>
<!-- End Google Tag Manager (noscript) -->

Note: Some Concrete CMS versions only have header tracking codes. In that case, you'll need to add the noscript via page template (see Method 2).

Save Settings
Clear Cache
- Go to Dashboard → System & Settings → Optimization → Clear Cache
- Clear cache to ensure code appears

Step 3: Verify Installation

Use GTM Preview Mode
- In GTM, click Preview button
- Enter your website URL
- Click Connect
- Navigate your site and verify GTM Tag Assistant shows events
Check Browser Console

Open browser developer tools (F12) and run:
```
console.log(window.dataLayer);
```
You should see an array (may be empty initially, but should exist).
Verify on Multiple Pages
- Homepage
- Blog posts
- Form pages
- Landing pages

Method 2: Page Template Installation

For more control or if built-in tracking codes aren't sufficient.

Step 1: Locate Theme Files

Your theme files are typically in:

/application/themes/[your-theme-name]/

Or for package themes:

/packages/[package-name]/themes/[theme-name]/

Step 2: Edit Page Template

Open your theme's main layout file (often view.php, default.php, or page_theme.php).

Add GTM Head Code:

Find the </head> closing tag and add above it:

<?php
// Exclude GTM from edit mode and dashboard
if (!$c->isEditMode() && !$this->controller->isControllerTaskInstanceOf('DashboardPageController')) {
    ?>
    <!-- Google Tag Manager -->
    <script>(function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':
    new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],
    j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src=
    'https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);
    })(window,document,'script','dataLayer','GTM-XXXXXXX');</script>
    <!-- End Google Tag Manager -->
    <?php
}
?>
</head>

Add GTM Body Code:

Find the opening <body> tag and add immediately after it:

<body>
<?php
if (!$c->isEditMode() && !$this->controller->isControllerTaskInstanceOf('DashboardPageController')) {
    ?>
    <!-- Google Tag Manager (noscript) -->
    <noscript><iframe src="https://www.googletagmanager.com/ns.html?id=GTM-XXXXXXX"
    height="0" width="0" style="display:none;visibility:hidden"></iframe></noscript>
    <!-- End Google Tag Manager (noscript) -->
    <?php
}
?>

<!-- rest of body content -->

Replace GTM-XXXXXXX with your actual Container ID in both places.

Step 3: Clear Cache and Test

Dashboard → System & Settings → Optimization → Clear Cache
Visit your site and verify GTM loads

Method 3: Theme Customization (Advanced)

For developers who want maximum control.

Using Concrete CMS Page Event

Add GTM code via page event in your theme's page_theme.php:

<?php
namespace Application\Theme\YourTheme;

use Concrete\Core\Page\Theme\Theme;

class PageTheme extends Theme
{
    public function registerAssets()
    {
        // Register assets if needed
    }

    public function getThemeName()
    {
        return t('Your Theme Name');
    }

    public function getThemeDescription()
    {
        return t('Your theme description');
    }
}

Then in your view files, add conditional GTM loading.

Using Header/Footer Assets

In your theme's elements/header.php or elements/footer.php:

<?php
$c = Page::getCurrentPage();
$app = \Concrete\Core\Support\Facade\Application::getFacadeApplication();
$u = $app->make(\Concrete\Core\User\User::class);

// Only load on public pages
if (!$c->isEditMode() &&
    !$this->controller->isControllerTaskInstanceOf('DashboardPageController') &&
    !$u->isSuperUser()) {
    ?>
    <!-- Google Tag Manager -->
    <script>(function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':
    new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],
    j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src=
    'https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);
    })(window,document,'script','dataLayer','GTM-XXXXXXX');</script>
    <!-- End Google Tag Manager -->
    <?php
}
?>

Excluding Admin and Edit Pages

Always exclude these from GTM tracking:

<?php
$c = Page::getCurrentPage();

// Check if NOT in edit mode AND NOT in dashboard
if (!$c->isEditMode() &&
    !$this->controller->isControllerTaskInstanceOf('DashboardPageController')) {
    // Add GTM code here
}
?>

Additional exclusions (optional):

<?php
$app = \Concrete\Core\Support\Facade\Application::getFacadeApplication();
$c = Page::getCurrentPage();
$u = $app->make(\Concrete\Core\User\User::class);

// Exclude edit mode, dashboard, and super users
if (!$c->isEditMode() &&
    !$this->controller->isControllerTaskInstanceOf('DashboardPageController') &&
    !$u->isSuperUser()) {
    // Add GTM code
}
?>

Configure GTM for Concrete CMS

Once GTM is installed, configure it to work with Concrete CMS.

1. Enable Built-in Variables

In GTM:

Go to Variables → Configure
Enable these built-in variables:
- Page URL
- Page Path
- Page Hostname
- Referrer
- Click Element
- Click Classes
- Click ID
- Click URL
- Click Text
- Form Element
- Form Classes
- Form ID

2. Create Concrete CMS Data Layer Variables

See Concrete CMS Data Layer Documentation for full variable setup.

Common variables to create:

Page Type:

Variable Type: Data Layer Variable
Data Layer Variable Name: pageType
Name: CMS - Page Type

Page ID:

Variable Type: Data Layer Variable
Data Layer Variable Name: pageID
Name: CMS - Page ID

User Type:

Variable Type: Data Layer Variable
Data Layer Variable Name: userType
Name: CMS - User Type

3. Create Concrete CMS Event Triggers

Form Submission:

Type: Form Submission
Name: Concrete CMS - Form Submit
Fires on: All Forms

File Download:

Type: Click - All Elements
Name: Concrete CMS - File Download
Fires on: Some Clicks
Condition: Click URL matches RegEx \.(pdf|doc|docx|xls|xlsx|zip)$

External Links:

Type: Click - All Elements
Name: Concrete CMS - External Link
Fires on: Some Clicks
Condition: Click URL does not contain \{\{Page Hostname\}\}

4. Publish Your Container

Click Submit in GTM
Name the version (e.g., "Initial Concrete CMS Setup")
Add description
Click Publish

Initialize Concrete CMS Data Layer

Add to your page template before GTM code:

<?php
if (!$c->isEditMode() && !$this->controller->isControllerTaskInstanceOf('DashboardPageController')) {
    $app = \Concrete\Core\Support\Facade\Application::getFacadeApplication();
    $u = $app->make(\Concrete\Core\User\User::class);

    $pageType = $c->getPageTypeHandle();
    $userType = $u->isRegistered() ? 'registered' : 'guest';
    ?>
    <script>
    window.dataLayer = window.dataLayer || [];
    dataLayer.push({
        'pageType': '<?php echo $pageType; ?>',
        'pageID': '<?php echo $c->getCollectionID(); ?>',
        'pageName': '<?php echo addslashes($c->getCollectionName()); ?>',
        'userType': '<?php echo $userType; ?>',
        'userID': '<?php echo $u->getUserID(); ?>'
    });
    </script>
    <?php
}
?>

Place this before the GTM container code.

Testing & Debugging

Use GTM Preview Mode

In GTM, click Preview
Enter your Concrete CMS site URL
Click Connect
GTM Tag Assistant opens in new window
Navigate your site and watch events fire in real-time

Debug Checklist

GTM container loads on all public pages
Container does NOT load in edit mode
Container does NOT load on dashboard pages
Data layer variables populate correctly
Custom triggers fire correctly
Tags send data to analytics platforms
No JavaScript errors in console

Common Debug Commands

Check if GTM is loaded:

console.log(window.google_tag_manager);
// Should show object with your container ID

View data layer:

console.log(window.dataLayer);
// Should show array with pushed data

Monitor data layer pushes:

const originalPush = window.dataLayer.push;
window.dataLayer.push = function() {
  console.log('Data Layer Push:', arguments[0]);
  originalPush.apply(window.dataLayer, arguments);
};

Performance Optimization

1. Minimize Container Size

Remove unused tags, triggers, and variables
Avoid adding too many tags to single trigger
Use tag sequencing for dependent tags
Regularly audit and clean up

2. Use Async Loading

GTM loads asynchronously by default. Don't modify this unless absolutely necessary.

3. Monitor Impact

GTM can impact Concrete CMS performance if not optimized:

Monitor Largest Contentful Paint (LCP)
Check Cumulative Layout Shift (CLS)
Keep container size under 200KB when possible

4. Consolidate Tags

Instead of installing multiple tracking scripts:

Install only GTM in theme
Add all tracking pixels through GTM
Remove marketplace tracking add-ons that duplicate functionality

Wait for user consent before firing marketing tags:

<script>
window.dataLayer = window.dataLayer || [];

// Check for consent cookie
const hasConsent = document.cookie.indexOf('tracking_consent=true') !== -1;

dataLayer.push({
  'event': 'consent_status',
  'analytics_consent': hasConsent ? 'granted' : 'denied',
  'marketing_consent': hasConsent ? 'granted' : 'denied'
});

// Listen for consent changes
document.addEventListener('consent_updated', function(e) {
  dataLayer.push({
    'event': 'consent_update',
    'analytics_consent': e.detail.analytics ? 'granted' : 'denied',
    'marketing_consent': e.detail.marketing ? 'granted' : 'denied'
  });
});
</script>

In GTM, create triggers based on these consent events to control when tags fire.

Troubleshooting

GTM Container Not Loading

Check:

Container ID is correct (GTM-XXXXXXX)
Script is in both <head> and <body>
No JavaScript errors blocking execution
Concrete CMS cache cleared
Not in edit mode or dashboard
Browser cache cleared

Data Layer Empty

Diagnosis:

console.log(window.dataLayer);
// Should return array, not undefined

If undefined:

GTM not properly installed
JavaScript errors blocking initialization
Cache not cleared

Events Not Firing

See Events Not Firing Troubleshooting for detailed debugging.

Container Loads in Edit Mode

Problem: GTM tracking when editing pages.

Solution: Add edit mode check:

<?php if (!$c->isEditMode()) { ?>
    <!-- GTM code -->
<?php } ?>

Changes Not Appearing

Problem: Updated GTM code doesn't show.

Solution: Clear Concrete CMS cache:

Dashboard → System & Settings → Optimization → Clear Cache
Or CLI: concrete/bin/concrete5 c5:clear-cache

Next Steps

Concrete CMS Data Layer - Complete data layer reference
GA4 Setup via GTM - Configure GA4 tags
Meta Pixel Setup - Add Meta Pixel through GTM

For general GTM concepts, see Google Tag Manager Guide.

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