Optimize your website's load time by minifying JavaScript files. Learn how minification improves efficiency, the tools you can use such as Webpack, Vite, and UglifyJS, and why it's essential for production. This guide explains the process and benefits of reducing JS file size to enhance site performance.
Are you seeing a warning about minifying JavaScript files in the website performance evaluation tool results like PageSpeed Insights?
We’ll talk about a couple of different ways you can resolve this issue so your website complies with this best practice standard.
So what does it even mean to minify a JavaScript file?
Basically, you’re reducing the file size as much as possible, which may include removing whitespace and anything else that doesn’t need to be in there for the source code to still work as intended.Furthermore, PageSpeed Insights will output potential savings and calculate how much you could reduce each JavaScript file size.
What is the purpose of minification?
But let’s take a step back and mention why we wouldn’t write code in such a way to omit this process. When we minify a JavaScript file, it becomes really hard to read and edit, because all the code is bunched up together, making it nearly impossible to understand the syntax and how it works. Therefore, we write code with indentations, comments and new lines to organize it and make it easier to understand.
In other words, we write code optimal for a human to understand, while we minify the JavaScript files, because only machines will be using them in production so it doesn’t matter if we can read it or not. Only thing that matters at that point is to make it as efficient as possible, so this is the main purpose of minifying or compressing.
What tools can we use for JS minification?
We can achieve minification by using build tools like Webpack or Vite, which have built-in functionalities for minification. All you need to do is enable it in the configuration file of the build tool.
In case you’re not using a build tool, you can also use a stand-alone tool like UglifyJS, which allows you to fiddle around with an array of options. Furthermore, it uses Node.js, so you’ll need to have that installed before you can install this tool and use it in the terminal.
In any case, we typically name files with minified code by using the name of the source code file and an extension .min.js.
Conclusion
To wrap it up, minifying JavaScript files is a standard best practice process to make JS files as efficient as possible when we’re optimizing a project for production. Furthermore, we talked about what tools we can use, whether we’re using build tools or not, bringing solutions for whatever the case may be for you.
