Your website’s page load time could be costing you serious money. The Aberdeen Group has calculated through their analysis that a, 1 second delay in page load time equates too:
- a 7% loss in conversions
- a reduction in 11% fewer page views
- and a 16% decrease in customer satisfaction
Putting that in dollar terms for a large online retailer, if your site typically earns $100,000 a day. Then this year you could lose $2.5 million in sales.
There are a number of ways that you can test the page load speed.
- Page Speed, an open source Firefox/Firebug add-on that evaluates the performance of web pages and gives suggestions for improvement.
- YSlow, a free tool from Yahoo! that suggests ways to improve website page load speed.
- WebPagetest shows a waterfall view of your page load performance plus an optimisation checklist.
- Google CodeSpeed – a free tool to analyse your code. Google offer a range of suggestions and how to improve the code for page load times
Secondly, Google have announced that page load speed does feed into their SEO algorithm. They have downplayed the importance at this stage but we expect that this will become more prominent moving forward, especially for mobile sites
A recent study by Web Performance Today analysed the top 500 online retailers to look at the performance and page composition of their sites.
They found 5 takeaways:
- Faster pages are smaller – Among the ten fastest pages, the median page contained 50 resource requests and was 556 KB in size. Among the ten slowest pages, the median page contained 141 resource requests and was 3289 KB in size.
- Faster pages have a faster Time to First Byte (TTFB) – Time to First Byte is the window of time between when the browser asks the server for content and when it starts to get the first bit back. The user’s internet connection is a factor here, but there are other factors that can slow down TTFB, such as the amount of time it takes your servers to think of what content to send, and the distance between your servers and the user. In other words, slow TTFB can be an indicator of a server problem or a CDN (or lack thereof) problem — or both.
- Faster pages understand their critical rendering path and know what to defer – Deferral is a fundamental performance technique. As its name suggests, deferral is the practice of deferring any page resources that are not part of a page’s critical rendering path, so that these non-essential resources load last. (The optimal critical rendering path has been excellently defined by Patrick Sexton as “a webpage that has only the absolutely necessary events occur to render the things required for just the initial view of that webpage”.)
- CDN adoption is the same among the fastest and slowest sites – Seven out of ten of the fastest pages used a CDN — as did seven out of ten of the slowest pages. This finding isn’t terribly surprising, as it goes hand in hand with the finding in our spring report that using a CDN doesn’t always correlate to faster pages.
- Adoption of other performance best practices is consistent (in its inconsistency) among the fastest and slowest sites – Looking at the ten fastest and ten slowest sites, we see that they all enable keep-alives, while none use progressive JPEGs. Image compression was hit-and-miss equally among both groups. It’s surprising, though, to still see so many sites not fully leveraging image compression, as this best practice has been around for years.