Updates on How Long People Will Wait for a Page to Load

Andrew King has a new post up highlighting recent research on how long people will wait for a page to load. Previously, the magic number was 10 seconds, but broadband has decreased our patience for slow sites.

A JupiterResearch survey found that 33% of broadband shoppers are unwilling to wait more than four seconds for a web page to load, whereas 43% of narrowband users will not wait more than six seconds (Akamai 2006).


Google found that moving from a 10-result page loading in 0.4 seconds to a 30-result page loading in 0.9 seconds decreased traffic and ad revenues by 20% (Linden 2006).

Plus a very real impact on sales:

Tests at Amazon revealed similar results: every 100 ms increase in load time of Amazon.com decreased sales by 1% (Kohavi and Longbotham 2007).

WordPress 2.5 Removes GZIP Option

WordPress 2.5 no longer provides an option to turn on gzip compression. According to Matt Freedman, the “option was axed for the reason that it’s better to enable compression on the server, rather than through WordPress.”

This is probably true because the option was turning on php compression instead of setting it in apache. However, it was still a surprise to realize my site was no longer being compressed.

To remedy the problem, I added the following to my .htaccess file in the root directory:

AddOutputFilterByType DEFLATE text/html text/css text/plain text/xml application/x-javascript application/json application/x-httpd-php application/x-httpd-fastphp application/rss+xml application/atom_xml application/x-httpd-eruby
Header append Vary Accept-Encoding

This is the code for Apache 2.0 as suggested by Ryan Williams. Similar code for Apache 1.3 can be found.

The main point is the if you used to rely on WordPress 2.5’s gzip option, you’re going to need to find an alternate solution.

Google Speeds Up Mobile Sites, Sees Traffic Increase

One of the reasons for my interest in site performance is because these techniques become even more important when developing for mobile. Google published some recent evidence supporting this belief.

“We saw something similar after we launched an updated interface for Gmail on the iPhone during MacWorld earlier this year. Lots of iPhone users tried the new interface (hence the bump in Gmail pageviews between January and February), but they didn’t stick around like we hoped they would. Over the course of the next few weeks, we made some tweaks to drastically improve the speed of the product, and Gmail pageviews on the iPhone not only stabilized, but began to rise, as the graph below shows:”


Read more at Google’s blog.

Page Load Time Means Money

One of the arguments I made in my presentation on site performance last year was that making small changes to your site to speed it up can make a big difference in your revenue. This was based on bandwidth savings.

However, now marketers using Google Adwords have an additional incentive to make their pages load quickly. Google is incorporating landing page load time as one of the factors for evaluating the quality ranking of an ad:

“Users value ads that bring them to the information they want as efficiently as possible. A high-quality landing page should load quickly as well as feature unique, relevant content. Fast load times benefit advertisers as well, since users are less likely to abandon a site that loads quickly.”

For companies that are spending thousands of dollars on text ads, ignoring their landing page load time could be spendy.

Automatically Version CSS and Javascript

The WuFoo guys have a great article on Particletree describing how they are handling automatic versioning of their css and javascript.

This allows you to set your css and javascript expires headers far into the future without worrying about browser caching getting in the way when you need to edit the files.

If you can bear with the confusing way comments are organized on Particletree, there is some good information on alternative methods in the discussion.

Steve Souders to Join Google

Steve Souders, Yahoo’s Chief Performance Officer and the author of High Performance Web Sites, is leaving Yahoo to join Google.

Most of the media coverage of his announcement has focused on a narrative of Yahoo’s demise. The Information Week article that I linked to above is probably the most neutral article I could find, and it still slants towards making a bigger deal of this change than it probably is.

I’m not much interested in whether or not this represents a larger trend for Yahoo. What matters for those who are concerned about site performance is that Steve has been publishing some of the best research recently on these topics. I hope he will continue to be able to publish new research and techniques while at Google.

Site Speed News

I’m catching up on a backlog of RSS feeds. I’ve got a few posts highlighting news that I missed. Hopefully it won’t be too out of date to be relevant.

Let’s start with two bits of news to pass along regarding site performance:

  • Study: Web Will Slow by 2010 — The increase in video usage is likely to saturate home internet provider networks. The study believes that speeds will decrease to dial-up levels. If this comes to pass, which I still consider a stretch, it will be more important to build fast sites.
  • YSlow-er — Yahoo released a new version of their YSlow plugin. Some of the changes may cause the grades for sites to drop. Details in the article. Update your firefox plugin to take advantage of the new features.