How to add iframes in flipbooks using Google Tag Manager

Overview

If you want to display third‑party content (chatbots, forms, banners) over your Flipsnack flipbooks, use Google Tag Manager (GTM) to inject a lightweight overlay. You’ll manage everything from GTM without editing the flipbook itself.

View example

Common use-cases

• Customer support chat: Add an Intercom, Drift, or Zendesk widget to assist readers while they browse your catalog.
• Lead capture forms: Embed a Typeform or Google Form to collect emails and grow your subscriber list.
• Feedback & surveys: Launch a survey after readers finish the flipbook to measure engagement or satisfaction.
• Marketing campaigns: Display a promotional banner or pop-up with discount codes, new product launches, or event invites.
• Educational content: Insert quiz forms, extra reading resources, or sign-up sheets for webinars and courses.
• Publishing & media: Show a “Subscribe to newsletter” overlay for magazines or newsletters embedded via Flipsnack.
• Internal communications: Use an overlay to link to company resources, policy acknowledgments, or HR forms inside corporate flipbooks.

How to create a Custom HTML tag in GTM

Before pasting any of the code examples, you’ll need to create a Custom HTML tag inside your Google Tag Manager container.

• Log in to Google Tag Manager and select the container used for your flipbooks.
• In the left-hand menu, click Tags.
• Click New → name your tag (for example, Flipbook iframe overlay).
• Click Tag Configuration → choose Custom HTML.
• Paste the code snippet provided in this guide.

• Scroll down to Triggering → click + to add a new trigger.

  • Choose Page View.

  • Select DOM Ready (recommended).
  • (Optional) Add a filter so it only fires on your flipbook URLs (e.g., Page URL contains flipsnack.com).
• Click Save.
• When you’re ready, click Submit and Publish in GTM to apply your changes.

Step-by-step instructions

Quick start (2 minutes): Paste‑and‑go overlay

Simplest path: Copy this into a Custom HTML tag in GTM, set the trigger to DOM Ready, and change only YOUR_FORM_URL.

<script>
(function(){
  var HTML = '' +
  '<div id="fs-quick-overlay" style="position:fixed;<strong>bottom</strong>:12px;right:12px;width:300px;height:400px;background:#fff;box-shadow:0 0 10px rgba(0,0,0,.3);z-index:2147483647;">' +
    '<iframe style="margin-top: 15px; margin-bottom: 15px;" src="<strong>YOUR_FORM_URL</strong>" title="Embedded form" style="width:100%;height:100%;border:none;"></iframe>' +
    '×' +
  '</div>';
function onBody(fn){ if (document.body) fn(); else requestAnimationFrame(function(){ onBody(fn); }); }
onBody(function(){
    if (!document.getElementById('fs-quick-overlay')) {
      var tmp = document.createElement('div');
      tmp.innerHTML = HTML;
      (document.body || document.documentElement).appendChild(tmp.firstChild);
    }
  });
})();
</script>

That’s it. No other edits needed. To move the box, change bottom/right values; to resize, change width/height.

Overlay with simple settings

Paste this one-file overlay script in GTM (Custom HTML, trigger: DOM Ready)

Why this is easy: All the settings you might change live in the CONFIG block at the top.

<script>
(function(){
  // ES5-compatible (no template literals / let / const)
  var FORM_URL = 'https://example.typeform.com/to/M6DYwFd0'; //<- CHANGE THIS WITH YOUR URL  
  var USE_BACKDROP = true;
// Cleanup helper
  function rm(id){ var el = document.getElementById(id); if (el) el.parentNode.removeChild(el); }
  rm('fs-overlay'); rm('fs-overlay-backdrop'); rm('fs-overlay-style');
// CSS string (no template literals)
  var cssText = ''+
    '#fs-overlay-backdrop{position:fixed;inset:0;background:rgba(0,0,0,.45);z-index:9998;}'+
    '#fs-overlay{position:fixed;top:50%;left:50%;transform:translate(-50%,-50%);width:90vw;max-width:800px;aspect-ratio:4/3;max-height:90vh;background:#fff;box-shadow:0 10px 30px rgba(0,0,0,.3);z-index:9999;display:flex;flex-direction:column;}'+
    '#fs-close{align-self:flex-end;margin:6px;background:#000;color:#fff;border:none;padding:4px 10px;font-size:18px;cursor:pointer;}'+
    '#fs-iframe{flex:1;border:none;width:100%;}'+
    '@media(max-width:480px){#fs-overlay{width:100vw;height:100vh;max-width:none;max-height:none;aspect-ratio:auto;border-radius:0;}}';
var css = document.createElement('style');
  css.id = 'fs-overlay-style';
  if (css.styleSheet){ css.styleSheet.cssText = cssText; } else { css.appendChild(document.createTextNode(cssText)); }
  document.getElementsByTagName('head')[0].appendChild(css);
// Backdrop
  if (USE_BACKDROP){
    var bd = document.createElement('div');
    bd.id = 'fs-overlay-backdrop';
    bd.onclick = close;
    document.body.appendChild(bd);
  }
// Overlay
  var box = document.createElement('div');
  box.id = 'fs-overlay';
var btn = document.createElement('button');
  btn.id = 'fs-close';
  btn.setAttribute('aria-label','Close');
  btn.appendChild(document.createTextNode('\u00D7'));
  btn.onclick = close;
var frame = document.createElement('iframe');
  frame.id = 'fs-iframe';
  frame.src = FORM_URL;
  frame.title = 'Embedded form';
box.appendChild(btn);
  box.appendChild(frame);
  document.body.appendChild(box);
// ESC to close
  document.addEventListener('keydown', function(e){ if ((e || window.event).key === 'Escape') close(); }, false);
function close(){
    rm('fs-overlay'); rm('fs-overlay-backdrop'); rm('fs-overlay-style');
  }
})();
</script>

GTM settings

• Tag type: Custom HTML
• Trigger: Page View → DOM Ready (fallback: Window Loaded)
• Filter: Limit to your flipbook URLs (e.g., Page URL contains your flipbook path)
• Firing options: Once per page

Modal placement options

Here are several ways you can display the modal depending on your use case:

1. Center modal (classic popup)

Best for: forms or surveys that need full attention.

<script>
(function(){
  var modal = document.createElement('div');
  modal.id = 'fs-modal';
  modal.style.cssText = 'position:fixed;top:0;left:0;width:100%;height:100%;display:flex;justify-content:center;align-items:center;background:rgba(0,0,0,.5);z-index:2147483647;';
  modal.innerHTML =
    '<div style="position:relative;width:420px;height:560px;background:#fff;padding:10px;">' +
      '<iframe src="https://yourform.typeform.com/to/abc123" title="Embedded form" style="width:100%; height:100%; border:none; margin-top: 15px; margin-bottom: 15px;"></iframe>' +
      '×' +
    '</div>';
  document.body.appendChild(modal);
})();
</script>

2. Bottom-right floating modal (shows immediately)

Best for: chat widgets or feedback tools that should stay visible while browsing.

<script>
(function(){
  var box = document.createElement('div');
  box.id = 'fs-modal-br';
  box.style.cssText = 'position:fixed;bottom:12px;right:12px;width:360px;height:520px;background:#fff;box-shadow:0 10px 30px rgba(0,0,0,.3);z-index:2147483647;';
  box.innerHTML =
    '<iframe src="https://yourform.typeform.com/to/abc123" title="Embedded form" style="width:100%; height:100%; border:none; margin-top: 15px; margin-bottom: 15px;"></iframe>' +
    '×';
  document.body.appendChild(box);
})();
</script>

3) Top banner that opens a modal

Best for: announcements or promotions. The banner stays pinned at the top with a button that opens a modal.

<script>
(function(){
  // Banner
  var banner = document.createElement('div');
  banner.id = 'fs-top-banner';
  banner.style.cssText = 'position:fixed;left:0;right:0;top:0;height:64px;display:flex;align-items:center;justify-content:space-between;padding:0 16px;background:#111;color:#fff;font:600 15px/1.4 system-ui,sans-serif;z-index:2147483647;';
banner.innerHTML =
    '<span>💬 Need help? Fill out our form</span>' +
    '<div>' +
      'Open form' +
      '×' +
    '</div>';
document.body.appendChild(banner);
// Modal
  var modal = document.createElement('div');
  modal.id = 'fs-modal';
  modal.style.cssText = 'display:none;position:fixed;top:0;left:0;width:100%;height:100%;justify-content:center;align-items:center;background:rgba(0,0,0,.5);z-index:2147483647;';
modal.innerHTML =
    '<div style="position:relative;width:420px;height:560px;background:#fff;padding:10px;border-radius:6px;box-shadow:0 8px 24px rgba(0,0,0,.3);">' +
      '<iframe src="https://yourform.typeform.com/to/abc123" title="Embedded form" style="width:100%; height:100%; border:none; border-radius:4px; margin-top: 15px; margin-bottom: 15px;"></iframe>' +
      '×' +
    '</div>';
document.body.appendChild(modal);
})();
</script>

What you can change

• Iframe URL: change the src="https://yourform.typeform.com/to/abc123" in each snippet.
• Modal size: edit width:420px;height:560px (or the bottom-right variant width:360px;height:520px).
• Banner labels: replace Open form with your text.
• Colors: change background:#111, #00AEEF, or color:#fff.
• Position: adjust top/bottom/left/right values (e.g., move the floating modal further from edges).

Additional tips / FAQs

• Can I target different flipbooks with different forms? Yes. In GTM, use URL-based triggers and duplicate the tag with different CONFIG.formUrl values.
• Can I delay the overlay? Yes. Wrap the inject()/create() call in setTimeout(function(){ ... }, 8000) (for 8s).
• Can I track interactions inside the iframe? Only if you control the iframe source and add tracking code there.

Common use-cases

• Chat widgets (Intercom, Zendesk)
• Feedback or survey forms (Typeform, Google Forms)
• Campaign banners and offers
• Lead capture and conversions

Troubleshooting

Overlay/modals don’t show

• GTM publish and trigger: Confirm GTM publishes and the trigger = DOM Ready.
• Tag firing scope: Check that the tag fires only on your flipbook URLs.
• Check node in DevTools: Open DevTools → Elements to see whether the node exists.

It loads twice

• Top-window guard and flags: Keep the top-window guard and global flags included above (window.self===window.top, __fsOverlayInjected, __fsPopupInjected).
• Optional in GTM: create a JS – IsInIframe variable and add it as a Trigger Exception.

Overlay covers player controls

• Adjust size and position: Tweak size/position in CONFIG (e.g., bigger bottom/right values).

Iframe refused to connect

• Embedding blocked by source: The source may set X-Frame-Options/CSP to block embedding. Try another provider or host your own page.

Next steps

• Customize the flipbook player
• Set up Google Tag Manager in your flipbooks
• Set up Google Tag Manager in Flipsnack

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