Fix duplicate analytics pageviews on Express with EJS

Start with the Express with EJS installation

Add the deferred tracker to the shared EJS partial that emits your document head. Include that partial through the existing local include pattern in each intended template. EJS has no built-in universal layout convention, so identify your actual application composition rather than assuming a views/layout.ejs file exists.

A res.send response or a separately rendered error template can bypass your usual partials. Keep the snippet in browser HTML rather than Express middleware that only logs requests. Never include a template path supplied directly by an untrusted visitor.

Use the public project key from the DataSag project you are inspecting. A test on a preview domain does not confirm that the production domain has the same code or settings.

Fix duplicate analytics pageviews in Express with EJS

1. Inspect the EJS head partial, wrapper composition and individual page templates together. A manual layout package may add a head that the child template also includes.
2. Search browser bundles and Express-served inline code for another tracker loader. Keep one owner in the generated document, preserving unrelated partials and route rendering logic.
3. Deploy and inspect two HTML routes directly. Count script elements after rendering and classify null-name pageviews separately from named interactions. If the app has custom client navigation, repeat that sequence to find repeated partial insertion.

The actual EJS-rendered document has one tracker after wrappers, includes and client updates are applied.

Complete the collection checks

1. Open Network and filter /api/track. Reload once without clicking or scrolling. Inspect eventName in each payload: null identifies a pageview; scroll, click_heatmap and __datasag_engagement are other records.
2. Count rendered script elements with data-datasag-key. There should be one intended installation for this project. Search your code, site header settings, embeds and tag manager for additional copies.
3. Remove redundant script insertion mechanisms, keeping the site-wide installation. Two copies execute independently even when their browser download is cached.
4. Check for custom router listeners that manually send pageviews. The current tracker handles pushState, replaceState and popstate and ignores a repeated pathname. Do not add a second pageview implementation without a demonstrated gap.
5. Repeat a direct load, a second route and browser Back. Correlate pageview records with actual path changes. A query-only change on the same pathname is not a new pageview in the current tracker.

[...document.querySelectorAll('script[data-datasag-key]')]
  .map(script => ({
    src: script.src,
    key: script.getAttribute('data-datasag-key')
  }));

What a successful check looks like

A single installation and one pageview dispatch for each actual pathname change in the tested sequence. Additional engagement records remain available.

Record the public path you tested, the browser state, the approximate time and the observed request. Check one direct page load and one later navigation so the result covers more than the homepage.

Common mistake

Comparing the total number of events with the number of pageviews produces a false duplicate diagnosis. Keep the event categories separate throughout the check.

Installation snippet for Express with EJS

The shared installation belongs in a shared EJS head partial included by the intended page templates. Use this as the installation reference while checking the procedure above.

<script defer src="https://www.datasag.com/tracker.js" data-datasag-key="YOUR_PUBLIC_KEY"></script>

Related Express with EJS guides

• Verify DataSag analytics
• Fix DataSag analytics not working
• Track custom events
• Track UTM campaigns
• Measure AI referral traffic
• Configure CSP for DataSag analytics
• Exclude your own analytics visits
• Load analytics without blocking rendering

Full Express with EJS setup guide · Search and AI visibility

References

Official Express with EJS documentation covers the integration point. For DataSag data handling, read the privacy policy. Use support if a request fails after these checks.