Fasterize Academy | How to Optimize My JavaScript with the JavaScript App

Introduction

JavaScript is essential for making your web pages interactive, but its size and execution can significantly affect loading speed.

Fasterize's JavaScript application lets you optimize your files using several complementary features: minification, bundling, SmartJS, and preloading.

The goal: to improve loading performance and provide a better user experience for your visitors.

💡 Learn more: Pitfalls to avoid for effective JavaScript loading optimization

How do I enable these features?

All of these optimizations are available in the JavaScript application via the Fasterize console. Each option can be enabled independently based on your needs.

JavaScript minification

Minification automatically reduces file sizes by removing spaces, comments, and unnecessary characters.

Fasterize applies this optimization by default, which allows you to:

to reduce bandwidth usage,
to speed up the browser's parsing and execution of scripts.

Bundling: combining scripts

The JavaScript Bundle option combines multiple external scripts into a limited number of files.

This grouping allows for:

to reduce the number of HTTP requests,
to limit network round-trip times (RTT),
and improve overall load time.

SmartJS: Postpone non-essential tasks

With SmartJS, Fasterize defers the loading of JavaScript functions that aren't called at startup.

This allows you to:

reduce the initial size of downloaded scripts,
execute the essential code more quickly,
cache the download of other critical resources (CSS, images).

“Only External” option

This option defers the loading of third-party scripts (widgets, tags, ads) only, in order to ensure that essential business logic continues to run.

Preload deferred scripts

The option Preload automatically adds an attribute rel=preload for scheduled scripts.