Service Worker
A service worker is a script that runs in the background in a user's web browser, separate from the web page. It acts as a programmable network proxy, giving a website the ability to intercept and handle network requests. Speed Kit uses the service worker as its core client-side technology to enable its most powerful features, including Dynamic Caching, Dynamic Content Merging, and Predictive Preloads, all directly on the user's device.
Related web performance terms
- Search Engine Optimization (SEO)
SEO is the process of improving a website's visibility in search engine results pages (like Google). The goal is to rank higher than competitors for relevant search queries to attract more organic (free) traffic.
- Server Response Time
Server Response Time is a component of Time to First Byte that measures how long the server takes to process a request and start sending back a response, excluding network latency.
- Server Timing
Server Timing is a browser API that allows the backend to communicate performance metrics about its own internal processes (e.g., database query time, time to render a component) to the browser via HTTP headers.
- Server-Side A/B Testing
This is a performance-friendly method for running A/B tests. Unlike Client-Side A/B Testing, the decision of which variation to show a user is made on the Origin Server.