WordPress is one of the most popular blogging platforms in the world. It’s fast, easy to use, easy to extend, and great at helping you hunker down and create great content. WordPress works out of the box on many different hardware and software configurations, with different url schemes, database setups, plugins, themes, et cetera. As a result, it has to make quite a few tradeoffs when it comes to performance.
So, you have your WordPress set up with the look and feel that you want, but how do you make it faster?
There are three primary things that make your site slow: lots of requests (too many external javascripts and stylesheets, as well as images), lots of data to send, and complexity of the page (tons of flash, really complicated javascript, etc.)
Here are five often overlooked but extremely useful tips you can use to speed up your WordPress blog dramatically, along with page load time benchmarks on a rather plain installation.
- Minify and combine your CSS and JavaScript
Combining your stylesheets and javascripts into at most one external file will cut down on the amount of connections the browser has to make in order to retrieve your page. This will result in dramatic speedups! Additionally, YUI Compressor can reduce the output size of your CSS and JavaScript considerably, and should be a mandatory process in getting your blog ready for handling a digging.
- Move CSS, Javascript, and Images to a CDN
A content delivery network will deliver your javascript, stylesheets, images, and whatever other content you have, to your users far faster than your site can. It works by putting lots of machines all over the world, and directing your users (transparently) to the machine closest to your user.Amazon CloudFront is great for this, using Amazon S3 as the storage behind it: it’s fast, cheap, and (relatively) painless to set up.When setting up a CDN, make sure to follow the next item, and additionally set a far future expires header. An Expires header that is set more than 48 hours in the future will prevent most browsers from bothering to request a file again to see if it is modified, and will make your site appear fast as greased lightning to repeat visitors!
- gzip your CSS, JavaScript, and html
While you are moving your CSS and JavaScript to a content delivery network, you should check to see what is required to send those files encoded with gzip – it reduces the size of the content transferred over the wire dramatically. Note that many people will mention that some browsers do not support this, so caveat emptor: if you are expecting users of 4.x browsers (eg. Netscape Navigator 4.x, Internet Explorer 4.x), you may want to check to see what files will work correctly when sent gzipped to these browsers. To enable gzipping of WordPress’ output, you can use a plugin like Gzippy.
- Check for duplicate javascript:
Multiple copies of prototype, jquery, etc. cut into both page load time and processing time. Try to stick to plugins that all use the same library, and try to do everything you can to not add any extra javascript at all. Remember that
- Avoid excessive use of any external content.
Most blog readers come to a blog for the content, and do not pay attention to or use items that come from external pages. If the flash/javascript/foobar is integral to the post’s content, put it after the jump so that it does not slow rendering of your index page for those who do not want to see that item. Particularly of note as of the time of this writing are:
- MyBlogLog – loads a huge flash element from minimally responsive servers
- Odiogo – their wordpress plugin loads a snippet of javascript in the head of the document, which blocks rendering of your page until their server has responded, in addition to excessive use of inline javascript in places that are obtrusive to users who don’t want to use text to speech.
