DataSag guides · Updated 27 October 2026

Load analytics without blocking rendering on React with Vite

Use the platform's non-blocking external script mechanism and install the tracker once. Measure the published page before and after the change; script size alone cannot predict the effect on your website. This guide applies to React with Vite.

Start with the React with Vite installation

Open the root index.html that Vite uses as its entry point. Paste the script into head once, outside the React component tree. Build and deploy the app, then inspect the deployed HTML. The tracker is a browser script and needs no npm package.

A React effect can run more than once during development or component remounts. Avoid inserting the tracker from useEffect when index.html already contains it. Development activity is not a substitute for checking the production build.

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.

Load analytics without blocking rendering in React with Vite

  1. Use defer on the external script in the root index.html and leave the application entry script intact. Avoid loading the tracker through a React effect that competes with component rendering or executes after repeated mounts.
  2. Build the app and measure its published document with fixed throttling and cache state. Compare tracker timing and first-action coverage alongside the page timing, rather than using the Vite development server as the baseline.
  3. Inspect a cold entry and later router navigation separately. A cached script still executes if inserted again, so a small transfer size does not prove the component tree avoids duplicate analytics work.

The production HTML loads the tracker without parser blocking, and the measurement distinguishes transfer cost from repeated execution.

Complete the collection checks

  1. Record a baseline of the published page using the same browser, device emulation and network settings you will use for comparison. Include a representative content page, not only the homepage.
  2. Use defer for a normal external HTML script, or the framework-specific loading strategy shown in the installation example. Do not add a parser-blocking synchronous script as a shortcut.
  3. Keep one installation in the shared document or layout. Duplicate execution adds work even if the browser reuses the downloaded file.
  4. Inspect the Network waterfall for tracker.js and /api/track. Compare transfer size, timing and request count on a cold load and a cached load.
  5. Check that measurement still starts at the intended point. Loading only after idle or interaction can omit short visits and early clicks; performance and coverage must be evaluated together.
  6. Repeat the measurements and record variability. Report measured results for your page rather than claiming a universal speed improvement or zero performance cost.
// Browser Console, after loading the published page:
performance.getEntriesByType('resource')
  .filter(entry => entry.name.includes('/tracker.js'))
  .map(entry => ({ url: entry.name, durationMs: entry.duration }));
// Cross-origin transfer details may be unavailable.

What a successful check looks like

The script uses a non-blocking loading mechanism, appears once and records the intended visits. Any performance claim comes from repeatable measurements of the actual site.

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

A faster lab result does not prove every visitor has a faster experience. Avoid mixing a warm-cache result with a cold-load baseline.

Installation snippet for React with Vite

The shared installation belongs in the head of the root index.html. 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 React with Vite guides

Full React with Vite setup guide · Search and AI visibility

References

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