Frontend Performance Optimization

2.1 What is Performance Optimization?

Performance optimization involves techniques and processes that make a web application faster and more efficient.

2.2 Critical Rendering Path

The critical rendering path is the sequence of steps the browser follows to convert HTML, CSS, and JavaScript into a rendered page. Understanding this path is essential for optimization.

3.1 Minification

Minification is the process of removing all unnecessary characters from code without changing its functionality. This helps in reducing file sizes.

const add = (a, b) => a + b;

3.2 Image Optimization

Images can be optimized by compressing them without losing quality and using appropriate formats (e.g., WebP).

3.3 Lazy Loading

Lazy loading defers the loading of non-essential resources during page load. This speeds up initial load times.

<img src="image.jpg" loading="lazy">

3.4 Code Splitting

Code splitting allows you to split your code into smaller chunks, which can be loaded on demand.

import(/* webpackChunkName: "my-chunk-name" */ './myModule').then(module => { ... });

4.1 Use a Content Delivery Network (CDN)

Utilize a CDN to serve assets from locations closer to the user, reducing latency.

4.2 Optimize CSS Delivery

Load critical CSS inline and defer non-essential CSS.

4.3 Monitor Performance

Regularly use tools like Lighthouse or PageSpeed Insights to monitor and improve performance.