Wordpress Running Slow?

Feb

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Slow WordPress

Question

“My website (which runs on WordPress) has been running really slow lately. I’m wondering if there’s something I can do to fix that. It’s on a server with a couple other websites and I have 14 plugins active. I didn’t know if I should move to my own server or if there’s an easier way to speed things up.”

Answer

Moving to your own better quality hosting is always a way to speed up performance but most likely the cause of your site running slow is the number of PHP calls happening on a given page. For example, if your blog’s home page loads your 10 latest blog posts – that’s 10 times the server has to make a call for data, not to mention your menu items and sidebar items. You could quickly have 30+ calls on a single page.

Another thing to think about is the number and size of the images your site is loading. Most of the time images are one the biggest causes of a site acting sluggish. If you upload full-size images then resize them in your code you’re definitely going to bog down the site. A general rule of thumb is only upload images at the size they should be displaying on a page – so just resize them first on your local computer before uploading them to your site.

A quick solution could also be installing a cache plugin for WordPress that will cache your images and/or pages on the server so that the server doesn’t need to run the PHP or call images each time someone loads a page. This could also protect you if your site gets on Digg.

Here are a few cache plugins that might be of interest but I’m not exactly sure which one to recommend as my site doesn’t currently have any caching plugins installed. Though, I probably won’t hesitate to install one in the future if I ever run into my site bogging down. Generally just make sure the plugin seems trustworthy and has a good rating before installing it.

Another note on caching…. If you do decide to install a cache plugin and need to make a change to an existing cached page, you may not be able to see the changes live on your site for 24hours or until the server caches the page again. It’d be cool if you could find one that does not cache pages for the admin. I’m not sure if any of the caching plugins do this though. If you find one with this feature please let me know.

Anyone else know of other good solutions?

Chester McLaughlin says:

February 12, 2010 at 11:09 am

I started writing up a comment detailing how to isolate your problem area(s) by testing your query and php execution time when I thought to myself… shouldn’t there be a plugin that does all this for you? Sure enough: http://wordpress.org/extend/plugins/debug-queries/

Install this plugin and see if you can find anything taking an inordinate amount of time (>1) to execute.

If you simply want to find out if your images are the problem, just install the Web Developer plugin for firefox and select “Disable Images” from the Images menu. https://addons.mozilla.org/en-US/firefox/addon/60

To really get your hands dirty and test performance you should get an apache/mysql/php environment running on your local computer so that you can quickly and easily experiment with different caching plugins and optimization techniques without fear of messing your site up.

OSX comes with apache built in, so you’ll only need to download and install the MySQL Community Server package from http://www.mysql.com/downloads/mysql/

Or you can install MAMP: http://www.mamp.info/en/mamp/index.html
Or on windows, WAMP: http://www.wampserver.com/en/