For general GTM concepts, see Google Tag Manager Overview
Overview
CMS Made Simple uses Smarty templates. Add GTM via the template editor in the admin panel.
Prerequisites
- A Google Tag Manager account with a Web container created at tagmanager.google.com
- Admin access to your CMS Made Simple site
- Your GTM Container ID (format:
GTM-XXXXXXX)
Installation
Where to Add GTM Code
Admin → Layout → Templates → edit your active template. Add head snippet before </head> and body snippet after <body>
GTM Head Snippet
Add this in the <head> section:
<!-- 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 -->
GTM Body Snippet
Add this immediately after the opening <body> tag:
<!-- 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) -->
Replace GTM-XXXXXXX with your actual Container ID in both snippets.
CMS Made Simple-Specific Considerations
CMS Made Simple templates use Smarty syntax ({literal}...{/literal}). Wrap JavaScript in {literal} tags or the Smarty parser will error on curly braces in the GTM snippet.
Template System
CMS Made Simple uses Smarty templates managed via admin panel. When editing templates directly, note that the GTM JavaScript snippet (inside <script> tags) will not conflict with the template engine's syntax.
Verification
After installation, verify GTM is working:
- GTM Preview Mode — In GTM, click Preview, enter your site URL, and verify the container loads.
- Browser Console — Open DevTools (F12) and run
console.log(window.google_tag_manager). You should see an object (notundefined). - Network Tab — Filter for
googletagmanager.comand verifygtm.jsloads with a 200 response. - Data Layer Check — Run
console.log(window.dataLayer)to verify the data layer array exists.
Next Steps
- Data Layer Setup — pass page and user data to GTM
- GA4 Event Tracking — configure GA4 via GTM
- Meta Pixel Setup — add Meta Pixel through GTM
- Troubleshooting — debug tracking issues