CSS and JavaScript optimization

Every web application has CSS and JavaScript files. Nowadays, it is common that most applications have lots of CSS and JavaScript files to make the application attractive and interactive. Each CSS and JavaScript file needs a browser to send a request to the server to fetch the file. So, the more the CSS and JavaScript files you have, the more requests the browser will need to send, thus affecting its performance.

Each file has a content size, and it takes time for the browser to download it. For example, if we have 10 CSS files of 10 KB each and 10 JavaScript files of 50 KB each, the total content size of the CSS files is 100 KB, and for JavaScript it is 500 KB—600 KB for both types of files. This is too much, and ...

Get PHP 7: Real World Application Development now with the O’Reilly learning platform.

O’Reilly members experience books, live events, courses curated by job role, and more from O’Reilly and nearly 200 top publishers.