Improving web page load times

The announcement by Google last month that they will be extending the Quality Score feature of AdWords to incorporate landing page load times will have implications for some advertisers whose rankings (or bid levels) may suffer as a result. Google says that faster loading pages should help to improve the effectiveness of a PPC campaign, since it is also a usability issue. So how can the page load times of a website be improved?

Load time is the length of time it takes for a page to load in the browser, so it can be dependent on the size of the page, the text content, images and underlying page code. Google says that a faster loading page creates a better experience for users, and therefore pages that take longer to load will be penalised as part of the Quality Score ranking criteria. Google will be including load time evaluations within the Keyword Analysis page available to AdWords advertisers, which will provide some indication of potential issues that might need to be reviewed to improve the performance of the landing pages.

Experts in this field say that 80% or more of the end-user response time comes from the ‘front end’ performance of a web page ‘ that is, how the browser deals with all the content with an HTML page, such as images, stylesheets, Flash content or scripts. If the number of these components can be reduced, then this will reduce the number of HTTP requests to display the page, which in turn results in a faster loading page. Very simply, by reducing the number of components on a page will speed up load times, but there can also be ways of reducing the number of HTTP requests while keeping the same content, such as by combining files or images, where appropriate.

Of course there are also factors that are out of the control of a website’s development team to speed up load times, such as the end user’s bandwidth speed, their ISP and proximity to the website’s server, but other design elements can also be used to a positive effect. Cleaning up the HTML coding or use of scripts on a page can make small differences to load times and putting stylesheets in the section of the web page will make pages load faster as the browser is able to render the parts of the page progressively.

In contrast, external JavaScript files work better if they are positioned as low in the page as possible since progressive rendering is blocked for all content below the script so that by moving scripts as low in the page as possible means there’s more content above the script that is rendered sooner.

Another important design element is to make JavaScript and CSS as external files. This generally produces faster loading pages because the JavaScript and CSS files are cached by the browser, so that the size of the HTML document is reduced without increasing the number of HTTP requests. The caching of these files won’t help the load time of a page for a new visitor but if they then view multiple page views and many of website’s pages re-use the same scripts and stylesheets, there is a greater potential benefit from having these external files cached.

With repeat visitors, using an ‘Expires’ header in the HTTP response will tell browsers how long a component on a page can be cached and so can reduce the number and size of HTTP requests in the future, making web pages load faster. However, this also has no effect on the load time for new visitors and if your website uses an Expires header you have to remember to change the component’s filename whenever the component changes.

If you are running an AdWords campaign you should start to consider how the landing pages from the advert link are loading and whether there are ways to increase this performance, either through a few small ‘quick fixes’ or by getting your web designers to implement more structural changes. This process should also be a way of reviewing the usability of your site for visitors and how effective your landing page is with the objective of converting new visitors to a desired action as quickly as possible.

If you’d like to know more about the Quality Score requirements for Google Ads (AdWords) or the load times for your website, please contact us now for a more detailed discussion.

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