Font Awesome 5：fa-svg-with-js.css等文件的差异与使用疑问

Hey there! Let me break down your questions clearly based on my hands-on experience with Font Awesome:

1. What's the purpose of fa-svg-with-js.css, and do I need it? #

fa-svg-with-js.css is a supplementary stylesheet built to pair with Font Awesome's SVG-with-JS loading method. Here's what it handles:

• Fixes vertical alignment glitches between icons and surrounding text
• Sets sensible default dimensions for icons (so you don’t have to define width/height from scratch for every icon)
• Provides base CSS rules for animation classes like fa-spin or fa-pulse
• Adds minor cross-browser compatibility fixes for edge cases

As for whether you need it: If you’re already using fontawesome-all.min.js and haven’t run into any styling issues (like misaligned icons, missing animations, or odd sizing), you can safely skip it. The JS library itself injects most necessary styles dynamically. But if you notice any visual glitches related to icons, adding this CSS file should resolve them.

2. How to use the tiny fontawesome.min.js (27KB), and why is it so small? #

That small JS file is Font Awesome’s core library skeleton—it only contains the basic logic to load and render icons, but no actual icon data (like SVG code for specific icons).

How to use it: #

You’ll need to load the core library first, then add the specific icons or icon packs you want to use. Here are two common approaches:

• Load pre-built icon packs: After fontawesome.min.js, include files like fa-solid.min.js (for all Solid-style free icons), fa-regular.min.js, or even individual icon files (e.g., fa-house.js if you only need that one icon).
• Manual library addition (for module bundlers): If you’re using tools like Webpack, you can import the core library, then import specific icons and add them to the Font Awesome library:

  import { library, dom } from '@fortawesome/fontawesome-svg-core';
  import { faHouse } from '@fortawesome/free-solid-svg-icons';
  
  library.add(faHouse);
  dom.watch(); // Automatically replaces <i> tags with SVG icons
  

Why it’s so much smaller: #

Unlike fontawesome-all.min.js, which bundles every free icon’s SVG code into one file (hence the 680KB size), fontawesome.min.js has no icon content at all. It’s just the "engine" that knows how to render icons once you feed it the specific icon data. This lets you load only the icons you actually need, drastically reducing your final bundle size.

内容的提问来源于stack exchange，提问作者Rangka Kacang