Alexa Ranking- Questions Finally Answered

Alexa is a website which ranks websites on the internet on the basis of their popularity.

I usually wondered how the Alexa ranking is calculated.

Is it based on the number of page views or the number of unique visitors or is it based on the number of sites linking to it.


One among the inquisitive few asked Alexa about it and this was the reply they gave:

Thank you for contacting Alexa Internet.

Alexa bases all ranking information on the web usage of Alexa Toolbar users. We do
not have access to any web site's private usage logs. For more detailed information
about Alexa's traffic rankings, you can visit:

http://www.alexa.com/site/help/traffic_learn_more

Now, as we said above, Alexa's traffic rankings are based on the usage patterns of
Alexa Toolbar users over a rolling 3 month period. A site's ranking is based on a
combined measure of Reach and Page Views. Reach is the percentage of internet users
who visit a site. Page Views are the average number of Alexa user URL requests for a
site, per Toolbar user. However, multiple requests for the same URL on the same day
by the same user are counted as a single Page View. The site with the highest
combination of users and Page Views is ranked #1.

Please also note that sites with relatively low measured traffic will not be
accurately ranked by Alexa. Alexa's data comes from a large sample of several
million Alexa Toolbar users; however, we do not receive enough data from our users
to make rankings over 100,000+ statistically meaningful. (Conversely, the closer a
site gets to #1, the more reliable its rank.) This means that, for example, the
difference in traffic between a site ranked 400,000 and a site ranked 800,000 is
statistically negligible. Sites ranked 100,000+ are subject to large ranking swings
due to the scarcity of data for those sites. In such cases, a single user (or the
lack of one) can make a dramatic impact.

We appreciate your interest in Alexa.

So alexa ranking largely depends on the number of visitors having alexa toolbar installed on their browsers.

For Lower ranking sites there can be a situation that the Alexa ranking is low compared to another site but has more number of page views than the other site.

So guarantee of Alexa ranking is only for sites having ranking less than 100,000