Usage share of web browsers

[
[http://marketshare.hitslink.com/report.aspx?qprid=0&qptimeframe=Q&qpsp=38 Market share for browsers, operating systems and search engines ] ] legend|#00ffff|Other (0.26%)] Usage share, in web browser statistics is the percentage of visitors to a group of web sites that use a particular browser. For example, when it is said that Internet Explorer has 74% usage share, it means Internet Explorer is used by 74% [ [http://marketshare.hitslink.com/report.aspx?qprid=0&qptimeframe=Q&qpsp=37 Market share for browsers, operating systems and search engines] ] of visitors that visit a given set of sites. Typically, the user agent string is used to identify which browser a visitor is using. The concept browser percentages for the Web audience in general is sometimes called browser penetration.

Overestimation and underestimation

Note that measuring browser usage in terms of the number of requests (page hits) made by each user agent can be misleading. Not all requests are generated by a user, as a user agent can make requests at regular time intervals without user input. In this case, the usage of that user agent would then be overestimated. Some examples:

*A web browser that refreshes the webpage at a regular time interval.
*Most browsers generate additional page hits by refreshing webpages when user navigates back through page history; only a few browsers (like Opera) reuse cached content without resending requests to server. [cite web|url=http://my.opera.com/yngve/blog/2007/02/27/introducing-cache-contexts-or-why-the|title=Opera Cache Contexts vs Security] [cite web|url=http://sharovatov.wordpress.com/2008/06/03/http-history-lists-and-back-button/|title=HTTP History Lists and Back Button]
*A feed reader that requests the RSS or Atom feed at a regular time interval.
*Extra files like CSS hacks and JavaScript hacks are often sent to Internet Explorer.
*Gecko-based browsers (such as Firefox) can link prefetch web pages, increasing hits. Link prefetching in Gecko-based browsers is used on pages with enhanced markup, including Google search results. [cite web|url=http://www.google.com/help/features.html#prefetch|title=Google feature list]
*A user who revisits a site shortly after changing or upgrading browsers may be double-counted under some methodologies; overall numbers at the time of a new version's release may be skewed. [cite web |url=http://www.computerworld.com/action/article.do?command=viewArticleBasic&articleId=9102398 |title=Firefox 3.0 boosts Mozilla's market share |accessdate=2008-06-27 |author=Gregg Keizer |date=2008-06-23 |work=Computerworld |publisher=IDG ]
*Certain anti-virus products fake their user-agent to appear to be popular browsers. This is done to trick attack sites that might display clean content to the scanner, but not to the browser. The Register reported in June 2008 that traffic from AVG Linkscanner, using an IE6 user-agent, outstripped human link clicks by nearly 10 to 1. [cite web |url=http://www.theregister.co.uk/2008/06/26/avg_disguises_fake_traffic_as_ie6/ |title=AVG disguises fake traffic as IE6 |accessdate=2008-09-05 |author=Cade Metz |date=2008-06-26 |work=The Register ]

It is also possible to underestimate the usage share by using the number of requests, for example:

*A graphical browser typically results in more hits than a text browser, as it downloads files referred to by the HTML document (e.g., image, CSS, and JavaScript).
*Many browsers and download managers spoof a different user agent string to the web server to prevent erroneous or malicious browser sniffing which could result in receiving broken or incompatible code, or being completely blocked, and thus increasing the statistics for other browsers (as an example, prior to version 9, the Opera web browser had "Identify as Internet Explorer" as the default user setting)
*Most recent browsers block third-party spyware.
*Text-based and audio-based browsers do not download any webbugs at all.
*Gecko-based browsers since Firefox 1.5 and Opera uses fast Document Object Model (DOM) caching. JavaScript is only executed on pageload from net or disk cache, but not if it is loaded from DOM cache. This can have an impact on JavaScript based tracking of browser statistics. [http://developer.mozilla.org/en/docs/Using_Firefox_1.5_caching]
*Ad filtering is popular through methods such as the Firefox extension Adblock.

Present to 1999

Net Applications

XiTi

Dataquest

ZD Market Intelligence

ee also

*Usage share of desktop operating systems
*Web browser
*Layout engine
*Market share
*Browser wars

References

External links

* [http://upsdell.com/BrowserNews/stat.htm Chuck Upsdell's Browser Stats] lists web stats from many different stats sources and gives the approximate current usage share of the most popular layout engines.
* [http://www.w3schools.com/browsers/browsers_stats.asp W3Schools' Browser Statistics] lists the web stats only from the W3 Schools site, which gives the approximate usage share of browsers among "people with an interest for web technologies."