DataSag guides · Updated 27 October 2026

Fix duplicate analytics pageviews on Eleventy

Multiple tracking requests do not necessarily mean duplicate pageviews. DataSag sends pageviews, scroll milestones, engagement updates and custom events. Inspect eventName before removing code. This guide applies to Eleventy.

Start with the Eleventy installation

Find the shared layout selected by your Eleventy data cascade, commonly an _includes/base.njk file. Add the deferred tracker to its head while preserving the content placeholder and existing template syntax. Build with your normal configuration and deploy the generated output. Layout paths depend on your project's directory settings.

Eleventy supports multiple template languages and chained layouts. A filename copied from an example may not be the active layout for your content. Inspect layout data and generated pages rather than assuming every collection uses the same wrapper.

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 Eleventy

  1. Search parent layouts, included head fragments and individual templates for tracker insertion. Chained layouts can emit a shared wrapper plus content that already contains a script, creating a duplicate in the final document.
  2. Inspect build transforms or plugins that inject analytics into HTML after templates render. Compare their output with the explicit head installation and choose one owner; source inspection alone can miss post-render injection.
  3. Build and inspect a generated page before opening it publicly. Reload once and separate pageview payloads from other event names. Repeat on a second collection layout to confirm the cleanup applies beyond the first template.

Final transformed HTML contains one installation across the tested layout chains, without overlapping build-time injection.

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 Eleventy

The shared installation belongs in the head of the shared layout resolved from your includes directory. 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 Eleventy guides

Full Eleventy setup guide · Search and AI visibility

References

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