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How do service-workers improve offline-cache and site speed?

Asked on Oct 07, 2025

Answer

Service workers enhance offline caching and site speed by intercepting network requests and serving cached resources, which reduces load times and improves reliability during offline access.

Example Concept: Service workers act as a proxy between the web application and the network. They can cache assets during the installation phase and serve them from the cache during fetch events, reducing the need for network requests and enabling offline access. This caching strategy improves site speed by delivering resources faster and ensuring availability even when the network is unavailable.

Additional Comment:
  • Service workers run in a separate thread, allowing them to handle requests without blocking the main thread.
  • They can implement different caching strategies, such as "cache-first" or "network-first," depending on the application's needs.
  • Service workers require HTTPS for security reasons, ensuring that the content served is not tampered with.
  • They are programmable, allowing developers to customize caching logic to optimize performance further.
✅ Answered with Core Web Vitals best practices.

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