Improving your website’s conversion rate doesn’t always require a full redesign or months of A/B testing. Sometimes, it’s about spotting and fixing the obvious friction points that frustrate your users.
In this guide, we’ll cover six simple things you can track using Google Tag Manager (GTM) that can lead to quick, meaningful conversion wins.
Jump to a section:
404 Page Views
JavaScript ErrorsRage ClicksDead ClicksOut-of-Stock Product ViewsSlow Loading Pages
Why track it?
Landing on a 404 page is a huge trust-breaker. It interrupts user flow and can cause immediate exits.
How to track it in GTM:
Create a Trigger: Trigger Type: Page View, Condition: Page Path or Page Title contains 404 or matches your site's 404 URL.
Fire a GA4 Event: Send an event like page_404_viewed to highlight how often this happens.
Pro Tip:
Set up an alert if 404 rates spike.
<script>
// 404 page detection
if (document.title.includes('404') || window.location.pathname.includes('404')) {
window.dataLayer = window.dataLayer || [];
window.dataLayer.push({
event: '404_page_view',
page_path: window.location.pathname,
page_title: document.title
});
}
</script>(Trigger this on All Pages or DOM Ready in GTM)
Why track it?
If core site features break (like forms or checkout buttons), users can’t convert - and many will leave without telling you.
How to track it in GTM:
Enable GTM’s Built-In Variable: Error Message, Error URL.
Set up a Custom Trigger: Trigger Type: JavaScript Error.
Fire a GA4 Event: Send an event like js_error_occurred with the error message as a parameter.
Pro Tip:
Filter out non-critical errors to focus on the ones that affect user journeys.
<script>
// JavaScript error tracking
window.onerror = function (message, source, lineno, colno, error) {
window.dataLayer = window.dataLayer || [];
window.dataLayer.push({
event: 'javascript_error',
error_message: message,
error_source: source,
error_line: lineno,
error_column: colno
});
};
</script>(Load once globally - auto captures all errors)
Why track it?
Multiple rapid clicks on the same spot often signal broken elements or confusing UX.
How to track it in GTM:
Set up a Click Trigger. Use a variable (like Click Classes or Click ID).
Use a Timer or Custom JavaScript to detect >3 clicks on the same element within a short time (e.g., 2 seconds).
Fire a GA4 Event: Name it something like rage_click_detected.
Pro Tip:
Combine rage click data with session recordings for deeper insights.
<script>
// Rage click detection
(function() {
let clickCount = 0;
let lastClickTime = 0;
let lastTarget = null;
document.addEventListener('click', function(e) {
const now = Date.now();
if (e.target === lastTarget && (now - lastClickTime) < 500) { // 0.5 second threshold
clickCount++;
if (clickCount >= 3) {
window.dataLayer = window.dataLayer || [];
window.dataLayer.push({
event: 'rage_click_detected',
element: e.target.tagName,
element_classes: e.target.className
});
clickCount = 0; // reset
}
} else {
clickCount = 1;
lastTarget = e.target;
}
lastClickTime = now;
});
})();
</script>(Detects 3 rapid clicks on the same element)
Why track it?
Users click on elements that look clickable but do nothing, causing frustration.
How to track it in GTM:
Create a Click Trigger that fires when a user clicks an element without a URL or action.
Example condition: Click URL is empty or missing.
Fire a GA4 Event: Event name like dead_click_detected, with element details passed as parameters.
Pro Tip:
Design clarity fixes dead clicks fast - either remove the affordance or make it actionable.
<script>
// Dead click detection
document.addEventListener('click', function(e) {
if (!e.target.href && !e.target.onclick) {
window.dataLayer = window.dataLayer || [];
window.dataLayer.push({
event: 'dead_click_detected',
element: e.target.tagName,
element_classes: e.target.className
});
}
});
</script>(Detects clicks on elements that don't have links or click handlers)
Why track it?
Landing on unavailable products kills buying intent and annoys users.
How to track it in GTM:
Use a DOM Element variable or scrape the out-of-stock message from the page.
Create a Trigger: Fire when the "Out of Stock" label/text is present.
Fire a GA4 Event: Send an event like out_of_stock_viewed with product details attached.
Pro Tip:
Prioritise restocking or hiding high-traffic out-of-stock items.
<script>
// Out-of-stock product detection
(function() {
const checkOutOfStock = function() {
const outOfStockElement = document.querySelector('.out-of-stock, .sold-out, [data-stock="out"]'); // tweak selectors for your site
if (outOfStockElement) {
window.dataLayer = window.dataLayer || [];
window.dataLayer.push({
event: 'out_of_stock_viewed',
product_name: document.querySelector('h1') ? document.querySelector('h1').innerText : ''
});
}
};
window.addEventListener('load', checkOutOfStock);
})();
</script>(Detects if any 'Out of Stock' message appears. Adjust the selector if your site uses a specific class or attribute)
Why track it?
Pages that load slowly (especially mobile) destroy conversion rates.
How to track it in GTM:
Use the page_load_time from built-in browser timings.
Set a Trigger: Fire if page load exceeds a threshold (e.g., 3 seconds).
Fire a GA4 Event: Name it slow_page_load_detected and pass the load time.
Pro Tip:
Identify high-value pages with slow loads (e.g., checkout, signup) first.
<script>
// Slow page load detection
window.addEventListener('load', function() {
const loadTime = window.performance.timing.loadEventEnd - window.performance.timing.navigationStart;
if (loadTime > 3000) { // 3000ms = 3 seconds
window.dataLayer = window.dataLayer || [];
window.dataLayer.push({
event: 'slow_page_load_detected',
load_time_ms: loadTime,
page_path: window.location.pathname
});
}
});
<script>(Fires if load time > 3 seconds. You can adjust the threshold)
You don’t need to track everything - but even adding just two or three of these can reveal huge hidden conversion blockers.
If you want help setting up these tags or running a deeper tracking audit,
Net Impression is a UK-based analytics consultancy, specialising in advanced GA4, GTM, BigQuery, and conversion rate optimisation for agencies and growth teams.