This is a question we are asked by people on a regular basis: “Why is my website slow?” The answer provided here, since 2012, is generally speaking in a WordPress context – because we are WP specialists – but a lot of the rules will apply to really any website, particularly one which runs on a Linux, Apache, MySQL and PHP setup.
Concatenation
Concatenation is a quite lengthy title to describe the process of combining multiple files together to make one file.
Most often, this process is used to combine multiple JS and CSS files into one file, which is downloaded once, instead of multiple files (from multiple sources).
When done right – in a manner which works!! – this can be combined with a CDN and give your website a real speed boost. Also browser caching can be employed to deliver near instant pageloads for your site.
Tools like WP Rocket and Autoptimize can help you to concatenate your JS and CSS files. Should also be used alongside other speed enhancements, such as minification, browser caching, a CDN, Varnish and choosing and using good WordPress hosting.
You may need to ask for expert help, though, as both JS and CSS can perform strangely when combined. If you suffer visual display issues, turn off these settings and consult an expert.
We use concatenation as part of our WordPress Optimization and WooCommerce Optimization services.