Conduct A Pagespeed Audit & Know Your Weaknesses

The first step to improve wordpress site performance from a loading speed aspect is to use the free site speed tool provided by GTMetrix to quickly gain a score for each of your website pages. The goal is to achieve a PageSpeed score of 100 and YSlow score of 95+ however in the spirit of making quick fixes we will aim to improve your page speed by performing 5 of the easier, less technical fixes.

1) Serve Scaled Images

Serve Scaled Images - Improve WordPress Site Performance

In the vast majority of cases, your website is going to be rendered on screens that use a 1920 x 1080 pixel display, therefore, even your largest images should only be 1920 x 1080 pixels large. GT Metrix analyses the size of your image containers on your website pages and recommends the exact size you should be using.
E.g. an image in a 600 x 400 px container may actually be 6000 x 4000 px in UHD from Shutterstock, by scaling this image in Paint using the resize tool, you can literally save MB's from your site, thus reducing loading time substantially.

2) Optimise Your Images

Optimise Your Images - Improve WordPress Site Performance

Using freemium tools such as TinyPNG, it is possible to reduce the size of your perfectly dimensioned images even further, reducing the file size by up to 80%. This is done through compression programs that use lossy compression techniques to minimise your image without much of a visual effect. 

TinyPNG offers the ability to optimise up to 20 images at a time for free on their website or if you seriously want to improve wordpress site performance, download their WordPress Plugin and compress your entire media library at once!

3) Specify Image Sizes

Whether you're building your website from a custom theme or using a visual page builder, it's highly recommended that you specify the width and height for all the images on your site. This allows for faster rendering by eliminating the need for unnecessary reflows and repaints and is a mildly technical way to improve wordpress site performance that may be the edge between you and your competitor's with respect to getting that elusive 100/100 speed score.

Google's current Page Speed test currently only detects image dimensions that are specified via the image attributes (e.g. Thumbnail being 150x150 px etc.), with site speed being a major ranking factor it is essential you specify the image sizes. Again, GT Metrix helps explain this for your particular pages on their test.

4) Optimise Your Site's Database Tables & Remove Page/Post Revisions

WP Optimize - Improve WordPress Site Performance

As you may know, WordPress (and all websites) are comprised of numerous files containing styles (CSS), content (HTML) and database queries (PHP). These are stored in a database and by default, when you make changes to a page on WordPress, the previous page layout and content files are retained as Post/Page revisions.

This means that the files are still in your database and whilst these files are generally very small, they can add up over time and also cause incompatibility issues with expired file headers etc. 

WP-Optimize is another WordPress freemium plugin that is designed to improve wordpress site performance by optimising your database tables to remove bloat and ensure efficient hierachy and linking. You can also remove all post/page revisions in one go along with trashed posts/pages and spam comments etc. 

Warning: We strongly recommend that you backup your site prior to optimising Database tables or removing post/page revisions. This is an irreversible process so maximum care should be taken.

5) Enable Website Caching

Whilst you might make a lot of changes to your site's pages when you're first building your site, once built the content of your main pages and even your blog pages doesn't change too much. In order to serve this content faster to your audience, you can use Caching plugins to create a static cache of all the files that make up your page. 

By presenting a unified cache of the files, it reduces the time to render the page. 

For caching, we recommend installing one of the following three WordPress plugins.

Finally, Build Your Knowledge With Website Speed Booster

We recently created a website that shows how we go about optimising the websites we build.

Incidentally, we optimised the website to score 100/100 on all popular website testers, such as Google Pagespeed Insights, GTmetrix and Pingdom. With website page speed being one of the primary factors for Google deciding to rank you, this is no longer a score to brush under the rug.