A few weeks ago the BBC ran an article (http://www.bbc.co.uk/news/technology-16300000) using data from Steve Souder’s HTTP Archive which suggested that page sizes had increased over the last year. This seemed to be in line with our own observations. After all we download over 1.2 Terabytes of data a day from over 2.44 million tests.
I wanted to see if this was the case using our own data so I took the top 10 sites from the (current) Hitwise top 50 e-tailers over the last 12 months (2011-01-01 to 2012-01-01) and plotted the recorded daily average page size.
What did we see?
In general, page sizes did increase over the 12 months studied.
The normal patterns observed were either a continual and gradual increase over time or a sudden increase in page size as the Christmas rush started. For example, John Lewis maintained a home page of between 300KB and 400KB for most of the year but we then recorded the start of a dramatic increase to a high of 1.2MB over the following few days. Page size has since started to decrease although it is still c. 820KB (well above the yearly median).
The Apple home page also varied considerably, noticeably surrounding 2 significant product launches. On the 3rd march the page size jumped from c. 665Kb to 980Kb for the launch of the iPad2, and then dropped back to 308Kb on the 28th April.
This was followed by another large increase (from 471Kb to 1.1Mb) on the 21st July following the release of the Mac OS X Lion Operating System.
What does this show?
That web sites in the main are becoming larger. This could be due to more flash / JS based content, the BBC article specifically referenced that JS was largely responsible (source: http://www.httparchive.org/trends.php#bytesTotal&reqTotal).
This also shows that the average number of requests for JS objects has also increased since the start of last year. This could indicate that pages are getting more dynamic / interactive but also that more 3rd party tags are being used (for things like user behaviour tracking, advertising and social ‘widgets’). The use of 3rd party tags needs to be closely monitored, given the SPOF (http://blog.patrickmeenan.com/2011/10/testing-for-frontend-spof.html) that they can introduce to pages.
Ultimately as we all know heavier pages will take longer to load (therefore reducing the end users experience) and cost site owners more to serve. Reducing page size where possible is going to improve any costs associated with the site (bandwidth, resource utilisation etc.) and will also help to ensure that users have a more pleasant browsing experience!
If you’re unsure how big your home page is right now, have a look at http://www.siteconfidence.com/test-your-site.aspx.