The need...for speed
Last month Greenlight revealed that 4% of the UK's most popular commercial websites had page load speeds slower than the acceptable threshold set by Google1, beyond which the advertiser may see increased click costs. Here are our top 5 methods for speeding you up.
1. Utilise content distribution
Much of your page load speed is related to the proximity of your content delivery system to your end users. The most common method of dealing with this inherent problem with proximity is by distributing your content across multiple geographical locations, creating what is known as a Content Delivery Network (CDN). A server in this network is selected to deliver the content based on its proximity to the requesting client, most commonly based on the number of hops away.
Creating your own CDN is typically only possible for large companies. However, smaller companies can use a CDN supplier, such as Limelight Networks or Akamai Technologies.
2. Reduce the number of HTTP requests
The vast majority of a page's download time is spent on rendering the front-end. Each front-end component is typically the end result of an http request for it. Reducing the quantity of these requests therefore reduces your total page load speed. Some of the best ways of achieving this are actually incredibly simple and should be considered best practise for your web development team. For example, combining all your CSS code into a single CSS file is relatively quick and simple, and can make a huge difference.
3. Cache-control and expiration headers
You can further reduce the number of http requests made to your server by communicating to the requesting browser that certain components on a page don't need to be retrieved again for subsequent pages. With static components you can do this by implementing expiration dates for those far into the future, essentially setting those components to never expire. With dynamic components you can utilise an appropriate Cache-Control header to aid the browser with conditional requests.
4. HTTP Compression
You can reduce the response times of your pages by compressing the http response using Gzip. About 90% of the world's internet traffic goes through browsers that support Gzip so this is a significant and cost-effective option.
Finally, you need to keep tabs on your site download speeds and there are a number of tools on the market to do this. Do a search for 'page speed tools' for a wide range of options, including off the shelf and open source provisions.