By Steve Claridge on 2014-03-15.

The speed of your website is very important; not only does a fast website make for happy users it can also improve your ranking in search engines.

The faster your website is the happier your users will be. People don't like waiting around and they especially do like sitting watching a white screen in their browser while your server struggles to serve up a web-page. People's attention-spans are short so your website needs to load quickly to give your content the best possible chance of being read.

Google stated a while back that website performance is now a factor that they consider when ranking websites in their search results. Basically, if you want to rank higher in Google then you need to make your site as quick as possible. Going by the performance graphs in Google's Webmaster Tools, Google considers a fast webpage to be one that loads in under 2 seconds.

So why is my WordPress site slow?

In this post I'm going to list some easy things you can do to try and speed your site up. In later posts I will go over the more technical changes to WordPress, and finally, some server-level stuff outside of WP. Before you make any major changes to your WordPress site it is essential that you make a backup first . Go on, go and backup your site right now, I'll wait...

Here's some simple, non-technical things to try and speed up your site:

Latest version of WordPress

Before you do anything else make sure you are running the latest version of WordPress itself. New versions of WP appear often and contain important bug fixes and enhancements, which includes performance improvements. If you are not sure if you are running the latest version simply login to your admin panel and if you need to upgrade you will see a little yellow information box at the top of your dashboard, it'll say something like, "Version 3.X.X is available, please upgrade". This should be safe and automatic but you have backed up your site already, haven't you?

Testing plugins

Plugins are great and add a vast amount of functionality to WP but sometimes they be a major drain on your site's performance. Not all plugins are created equal - some slow your site down due to being badly written and others are a performance hog simply because they are doing a lot of work. To find out if any of your installed plugins are causing a problem do this:

  1. Go to your admin panel and disable one of your plugins.
  2. Try browsing your site to see if removing the plugin made any difference.
  3. If the plugin didn't make any difference - or you simply must keep it - re-enable it.
  4. Repeat #1 with the next plugin.

It is important to disable only one plugin at a time; if you disable more than one and you do see a performance improvement then you will not know exactly which of the plugins you disabled is causing the problem.

Delete any plugins you no longer want. No sense in having them installed if you don't need them.

Install a Cache plugin

There's a few caching plugins around that will make a huge difference to your site's performance. The downside to these is that they tent to use technical based terms; luckily, though, they usually have a good set of default options and don't require any configuration.

What do these plugins actually do? Without one of these plugins installed WordPress will, when asked to display a webpage: read your post's content from the database, read your theme's file from disk, insert the post data into the theme, read in any other data the theme wants to display (comments, category names, other post links, etc) and insert it into the theme, and finally send the completed page to the user's browser. It does that pretty quickly but it can slow down considerably as traffic increases.

What a cache plugin does is to save a copy of the completed HTML webpage just before it gets sent to the user's browser. This means that the next time the same page is requested the process is much quicker, WordPress only has to load that saved version of the HTML and send it to the browser, all of the reading from the database, and so on, does not have to be done again.

At the moment I use the W3 Total Cache plugin. I'm writing my own performance plugin but until that it ready W3 Total is a great; it does have a lot of very-technical settings and options but you can install it and not have to change anything, the default settings are good enough in most cases.

That's the easy things

The three things above are super-easy non-technical things that anyone can do. The first two might not improve speed radically for most people but a rogue plugin may just be causing your slowness so its worth having a look at them. The third tip, the cache plugin, will make a huge difference to any WP site.