The goal of web performance optimization is to become faster and smaller: research at Yahoo! and Google found that just 10-20% of the perceived loading time is caused by the server. A few years ago we thought performance was exclusively connected to the server. However, 80-90% of the loading time incurs in the frontend. Thus WPO is more efficient targeting the frontend.

Two important weak points are JavaScript files and the sheer number of files: JavaScript loads sequentially and blocks subsequent code until each file is loaded. Hence it shouldn’t be located in the head, but in the foot of a page. Secondly older browsers, in particular Internet Explorer, will only load 2-4 files in parallel. Files queue up and get processed when it’s their turn. Therefore aggregation of files is used for reducing the number of HTTP requests.

Several international companies have conducted research or just tracked the effects of optimization.

Effects of slowness

• Amazon: 100 ms delay caused a 1% drop in revenue.
• Google: 400 ms delay caused a 0.59% decrease in search requests per user (earlier tests list larger numbers).
• Yahoo!: 400 ms delay caused a 5-9% decrease in traffic.
• Bing: 2 seconds delay caused a 4.3% drop in revenue per user.

Effects of speed

• Mozilla made their download page 2.2 seconds faster and was rewarded with an increase of 15.4% in downloads.
• Google Maps reduced the file volume by 30% and observed a 30% increase in map requests.
• Netflix enabled gzip on the server; simply by this single action pages became 13-25% faster and saved 50% of traffic volume!
• Shopzilla succeeded in reducing the loading time from 7 down to 2 seconds, whereby the conversion rate increased by 7-12%, they observed a 25% increase in page requests, they were able to retire 50% of their servers, thus saving energy costs.
• AOL observed the number of page views on several websites. While the fastest users requested 7-8 pages, the slowest only viewed 3-4.

As a cream topping Google recently announced to factor in the site speed as a parameter in web search ranking.

Eventually pages become faster, clients are happy, generate more revenue and page views, while power consumption and CO₂ emissions decrease. Saved the world, again! And if you’d like to contribute, start by checking the rules at Yahoo! A few tricks beyond that can be found in the presentation which will be translated soon.

The presentation is now available for download in English or German under a Creative Commons license, so you can re-use material as long as you quote me.

Let’s face it: all of us have heard the phrase “blind people are not our target group,” either from clients or colleagues. There are a few noble souls who actually care about other people’s needs, but business is mostly about money.

So I explained how businesses lose money by ignoring accessibility. Because accessibility is not only about blind people: it’s about color blind, about old people, young people with learning disabilities, or people who are not fluent in a language. Fundamentalists will deny, but there’s also a close relation to device independence.

You may decide to ignore “a few disabled,” but you cannot ignore half of the population: accessibility is becoming a social and economic imperative.

1. The geek meeting in Frankfurt known as Webmontag will be held for the seventh time at the Brotfabrik. So far there are short lectures about a social photosharing network, semantic webworking P2P transactions, and a wireless match maker, but you are free to present your own work and research.

   After all, this is an informal meeting organized through a Wiki where you can participate and share your knowledge. Not necessarily technical knowledge, also designers, project managers, and information architects have been spotted — I wish they would speak up more often. Admission is free, so if you are in the Frankfurt area you have no excuse not to attend.

2. The second conference almost slipped my radar: it’s the First European e-Accessibility Forum in Paris, organized by the French accessibility entity BrailleNet and EDeAN (European Design for All e-Accessibility Network). While I can’t say much about BrailleNet, EDeAN is the official accessibility outreach organization of the EU. So far they have kept a low profile doing politics and research in the background, but it’s about time more people learn about their existence.

   For only € 90 you get a day packed with high quality accessibility information from industry leaders: Microsoft’s French Technical Director speaks about accessibility in the Web 2.0 context. IBMs Rich Schwerdtfeger, member of both the WAI Protocols and Formats Working Group and the HTML Working Group, is next with accessible rich internet applications (ARIA). Among other speakers, there will be Christian Heilmann (Yahoo!), Michael Cooper (W3C / WAI), Steven Faulkner (developer of the Web Accessibility Toolbar), Dave Wilton (Legal & General, the insurance company that got best practice credits in the UK’s PAS 78), Julie Howell (former accessibility champion of the Royal National Institute of the Blind), Dominique Hazaël-Massieux (W3C), and Miguel González-Sancho (European Commission). They will talk about accessibility and the Mobile Web, the UbiWeb, harmonization of European accessibility and a European label, or present a couple of case studies from print, banking, and job websites.

   You better be fast for that one, registration is only open until Saturday, January 20th.

3. Last but not least the website for the @media conference has been updated yesterday, so you can register for the event in London, June 7th and 8th, or earlier in Asia and the US. Last year’s event was fun and inspirational, so start fast-talking your employer now!