Why speed up your site in the first place?

Its becoming increasingly important to make your website load faster. With faster internet connections end users have increasing expectations of how fast a site should load. Studies have consistently shown that differences as small as 100ms to page load times have measurable effects on conversion rates, bounce rates, page views etc. Page speed is also a signal in Google's ranking algorithm so you could be getting penalised if your site is slow compared to your competitors.

First steps

The first thing you should do is take a baseline measurement of the performance of your site. We recommend webpagetest.org to do this for a couple of reasons.

  1. It is free and comprehensive
  2. It allows you to choose from a wide range of geographic locations, you want to test where your audience is.
  3. It doesn't send no-cache directives in the request. If you have a caching proxy server that honours the no-cache directive then the results aren't going to reflect real world performance of your site, it will be measuring the performance of your server.

Once you've got a baseline you can get started.

Next...

1. Upgrade PHP

PHP is getting faster and more memory efficient with every release. The jump from 5.x to 7.x being the most significant. However upgrading is sometimes easier said than done. If you are in a shared hosting environment you might not have any control over what version of php you're running, if you don't then you should at least have a php accelerator like opcache installed. If your host is still on php 5.x and doesn't have opcache then it might be time to consider a new host. If you do have the option to upgrade then you should do it, taking all the necessary precautions like taking a backup and testing your plugins and them are all compatible with the version you're upgrading to.

2. Deactivate/uninstall unused plugins

Even if they're not being used they could be adding to the size of the page, the number of requests to your server and the effort required for your server to generate a page.

3. Reconsider your theme

Many Wordpress themes are very 'heavy', they include a lot of javascript and css for fancy effects you probably will never need. All this unnecessary bulk will slow download speed and also render speed. Choose a theme as light as possible, it might just be time to say goodbye to the slider in the hero section of your current theme. Sliders add considerable weight to the size and render speed of a page.

Some themes will also load resources that are external to your site, eg fonts from google and javascript from cdns. Sometimes this is a good thing but in general the less domains your client's browser has to connect to the faster your site will load.

4. Only accept HTTPS

Google favours secure only sites and HTTP version 2 only operates over SSL, HTTP/2 alone can make sites significantly faster and you might be missing out if you accept unencrypted traffic.

5. Optimise your content

This includes

  1. Image optimisation
  2. Code minification
  3. Gzipping content

Advanced

Wordpress background tasks

Database optimisation