An Entity tag (ETag) is a unique identifier assigned to a specific version of a given resource on a web server. ETags are used as a cache control mechanism to allow client browsers to make conditional requests. This lets caches work more efficiently by reusing unchanged resources on the client, and avoiding full server responses if the content has not changed. Efficient caching saves bandwidth and improves performance by delivering only what the client needs, not what it already has.
Website optimization
Automatically Speed Up Your Site with mod_pagespeed for Apache
mod_pagespeed is an open-source Apache 2.2+ module designed to automatically speed up your site by optimizing the various components of your web pages. The module does this by rewriting page resources using filters that adhere to web performance best practices. mod_pagespeed is the server version of the client-side Firefox module that analyzes web pages using similar best practices.
What to Expect from a Web Performance Audit – get better search engine rankings with website performance audits
With Google now factoring page loading speed into search engine rankings, having a fast website has become even more important. Exactly how much of a factor speed is in search rankings is open to debate, although anecdotal evidence suggests that speed can affect rankings. One of the first steps companies need to take in improving their website speed is a web performance audit. This article details what to expect in a web performance analysis.
Andrew King Interviewed by Joshua Bixby of Strangeloop Networks
Our own Andy King was interviewed by Joshua Bixby of Strangeloop Networks. Joshua asked Andy some probing questions about web performance consulting.
Velocity 2010 Web Performance Conference
I just got back from the Velocity 2010 Web Performance and Operations Conference in Santa Clara, California. Now in its third year, the conference is a must-see if you are a web performance or network operations engineer. And engineers were aplenty this year, the conference was sold out with more than 1500 attendees.
Page Speed Factored into Google Search Rankings
Google has incorporated the speed of a web page into its search engine rankings. While
this new signal currently affects only a small percentage of US sites, Google’s announcement officially links performance with search engine marketing.
PNG24 and PNG Optimization – learn how to optimize PNG files for smooth alpha transparency and small file size
Over 60% of the file size of the average web page is taken up by graphics and multimedia. So graphics optimization is an important step in optimizing web page speed. At an alarming frequency, we have seen large PNG24 and unoptimized JPEGs used on the Web. Large PNG24s should be optimized for file size or converted to PNG8s. This article shows how to optimize PNG files effectively by minimizing their color palettes, and using alpha transparency intelligently.
Anatomy of a Redesign
WebsiteOptimization.com was designed by the author in 2002, in the age of slower dial-up modems. The design was starting to show its age, so we’ve been quietly working on a redesign to improve the look and conversion rate. This article shows how we redesigned the site, and some of the techniques we used to achieve our goals.
Memory Markers and the Subjective Duration of Experience – consumer recall of the duration of rich and impoverished experiences in cognitive psychology
Online marketing has evolved from selling products to creating engaging experiences for consumers. New research shows that how long these experiences seem to last, however, depends on how rich the experience and time of recall (Ahn, Liu, and Soman 2009). The “memory marker” model helps explain this phenomenon and the time distortion that some people experience during and after immersive online flow experiences. Web developers need to balance the need to create rich online experiences with tolerable download times and scant distractions.
Web Page Performance Thesis – web page response time measurement, modeling and monitoring
For his doctoral thesis at the University of Glasgow, Thiam Kian Chiew studied web page performance. As part of his research, Chiew explored the different factors that affect web page speed, testing and modeling the key components to web page download times. His findings are summarized below.