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How can I reduce JavaScript execution time to improve my site's interactivity?
Asked on May 14, 2026
Answer
Reducing JavaScript execution time is crucial for improving a site's interactivity, especially for the First Input Delay (FID) metric. This can be achieved by optimizing the way scripts are loaded and executed.
<!-- BEGIN COPY / PASTE -->
<script src="script.js" async></script>
<!-- END COPY / PASTE -->Additional Comment:
- Use the "async" attribute to load scripts asynchronously, allowing the browser to continue parsing HTML while the script is being fetched.
- Defer non-essential scripts to prevent them from blocking the main thread during page load.
- Minify and compress JavaScript files to reduce their size and improve download times.
- Consider code splitting to load only the necessary JavaScript for the current page.
- Analyze JavaScript execution using tools like Chrome DevTools to identify and optimize long tasks.
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