Web Development Advanced

What is Service Worker?

A JavaScript file that runs in the background, enabling offline support, push notifications, and background sync for web apps.

Service workers act as programmable network proxies between the browser and server. They intercept network requests, cache resources, and serve cached content when offline. This enables Progressive Web App (PWA) capabilities.

The lifecycle includes registration, installation (cache assets), and activation (clean old caches). The fetch event handler implements caching strategies: cache-first, network-first, stale-while-revalidate. Service workers also enable push notifications and background sync.

Learn More About This Topic

TypeScript for Backend Developer

Related reading

JavaScript ES6+ Modern Features

Related reading

JavaScript Fundamentals

Related reading

Related Terms

Structured Data (Schema.org)

A standardized vocabulary for marking up web content so search engines can understand and display it as rich results.

API Rate Limiting

A strategy for limiting the number of API requests a client can make within a specified time window to protect server resources.

A mechanism where a server sends real-time HTTP POST notifications to a specified URL when specific events occur.

Brotli Compression

A modern compression algorithm developed by Google that achieves better compression ratios than Gzip for web content delivery.

A technique that delays loading non-critical resources until they are needed, improving initial page load performance.

JavaScript Object Notation — a lightweight data interchange format that is easy for humans to read and machines to parse.

View All Web Development Terms →