Overview
Everyone knows first hand that page load time is an important component of user experience on a website.
57% of web page visitors leave after 3 seconds load time
85% leave after 5 seconds
66% expect page to load in less than 4 seconds
27% of mobile users complain that sites load too slowly on their phones
26% of mobile users give up when site loads too slowly
The Page Load Time report is a starting point for spotting long load time problems and troubleshooting them.
Most of the time the Page Load Time report confirms that your site is loading quickly. Even if the report shows a small percentage of pages taking a long time to load, that reflects the nature of the web. Most audits will reveal some pages that take a long time to load, and those long load times could be a random network issue that may not be easily repeatable.
Best Practices
A small percentage of long load times indicates your site is loading quickly for the overwhelming majority of pages. This is a good sign, and there is nothing you need to do. But there are situations where you need to troubleshoot and fix problems. The following guidelines will give you some direction.
When Not to Troubleshoot
Troubleshooting a small number of slow loading pages can cost a great deal of time, especially if you can't reproduce the problem on those pages. Unless the slowdowns are on highly trafficked pages, it is generally unproductive to aim for no slowness whatsoever in your audit reports.
In practical terms, a few slow pages out of 1000 page views means the user experience is probably not noticeably slow. An occasional slow page happens due to a number of environmental and technological factors over which you may have little or no control.
There are likely larger problems to fix that will result in greater user satisfaction than the infrequent slow page.
When to Troubleshoot
If you see a large percentage of slow pages or a sudden and sharp increase in the number of pages loading slowly, it may mean there is a significant problem. It could be caused by a network slowdown, overloaded servers, heavy page content, or slow loading tags.
Begin with these steps to troubleshoot:
Check the network: If there is a current network slowdown, you can likely see that by browsing to any of the slow loading pages of the site. Use an external network if possible because using the in-house network may not replicate the actual public user experience. If the pages load fine, the problem may have been resolved since the audit was run.
Check the audit browser: Load a sample of the slowest loading pages with the same user agent string that the audit used in order to see if the pages actually take a long time to load. If they don't, it could mean there was a site issue during the time of the audit. In that case, the problem may already be resolved.
Confirm that the issue is resolved by running a quick 100 page audit based on a sample of pages that loaded the slowest.
Open the Page Load Time report in the new audit to see if the pages still show as loading slowly.
If you still see the issue, continue with these troubleshooting steps. Otherwise, the problem was likely due to a temporary network or website issue that has since been resolved.
Check a different browser: Load a sample of the slowest loading pages using a different user agent string (browser) from the audit. If the pages don't appear to run slowly, it may be a browser issue.
To confirm, run a quick 100 page audit based on a sample from the slowest loading pages but using a different user agent from the original audit.
If you still see the issue, it is likely not a browser issue.
Check tag load performance: Open the Tag Hierarchy on slow loading pages. Examine the tags to see if any are loading slowly by hovering the mouse over the tag name and looking at the Loadtime metric in the tooltip. A large number of marketing tags loading on a page can lead to slow page loading and result in some data not being captured because the user moves on before all the tags load.
Look at JavaScript errors: Check slow loading pages in a browser to see if they produce a large number of JavaScript errors. Open the browser's JavaScript console, load the page, and see if there is an unusual number of JavaScript errors or alerts that may be affecting the load time.
Check the page size: Heavy pages will load slowly. If you have QueryBuilder enabled for your account, check to see if the slow loading pages have a hefty byte size.
If these steps do not help you isolate the problem, contact your Customer Success Manager for more in-depth troubleshooting.
* Optimize Performance For Global And Mobile eCommerce, March 2016, Forrester