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How can I reduce JavaScript execution time to improve site interactivity?
Asked on Feb 02, 2026
Answer
Reducing JavaScript execution time is crucial for improving site interactivity and enhancing the First Input Delay (FID) metric. This can be achieved by optimizing the way JavaScript is loaded and executed in the browser.
Example Concept: To reduce JavaScript execution time, consider splitting your JavaScript into smaller chunks using code-splitting techniques. This allows the browser to load only the necessary scripts for the initial page load, deferring less critical scripts for later. Additionally, use the "defer" attribute on script tags to ensure that JavaScript execution does not block the parsing of HTML, allowing the page to become interactive more quickly.
Additional Comment:
- Minify and compress JavaScript files to reduce their size and improve load times.
- Use asynchronous loading for third-party scripts to prevent them from blocking the main thread.
- Implement tree shaking to eliminate dead code from your JavaScript bundles.
- Regularly audit your JavaScript dependencies to remove unused libraries.
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