Some Important Disclaimers
The traffic data are based on the set of toolbars that use Alexa data, which may not be a representative sample of the global Internet population. Known biases include (but are likely not limited to) the following:
Our users are disproportionately likely to visit sites that are featured on alexa.com such as amazon.com and archive.org, and traffic to these sites may be overcounted.
The extent to which our sample may overcount or undercount users of the various browsers is unknown. Alexa's sample includes users of Internet Explorer, Firefox and Mozilla browsers. The AOL/Netscape and Opera browser is not supported, which means that sites operated by these companies may be undercounted.
The extent to which our sample may overcount or undercount users of various operating systems is unknown. Alexa sample includes toolbars built for Windows, Macintosh and Linux.
The rate of adoption of Alexa software in different parts of the world may vary widely due to advertising locality, language, and other geographic and cultural factors. For example, to some extent the prominence of Chinese sites among our top-ranked sites reflects known high rates of general Internet usage in China, but there may also be a disproportionate number of Chinese Alexa users.
In some cases traffic data may also be adversely affected by our "site" definitions. With tens of millions of hosts on the Internet, our automated procedures for determining which hosts are serving the "same" content may be incorrect and/or out-of-date. Similarly, the determinations of domains and home pages may not always be accurate. When these determinations change (as they do periodically), there may be sudden artificial changes in the Alexa traffic rankings for some sites as a consequence.
The Alexa Toolbar turns itself off on secure pages (https
. Sites with secure page views will be under-represented in the Alexa traffic data.
In addition to the biases above, the Alexa user base is only a sample of the Internet population, and sites with relatively low traffic will not be accurately ranked by Alexa due to the statistical limitations of the sample. Alexa's data come from a large sample of several million Alexa Toolbar users; however, this is not large enough to accurately determine the rankings of sites with fewer than roughly 1,000 total monthly visitors. Generally, Traffic Rankings of 100,000+ should be regarded as not reliable because the amount of data we receive is not statistically significant. Conversely, the more traffic a site receives (the closer it gets to the number 1 position), the more reliable its Traffic Ranking becomes.
