Why does the directly-measured data differ from my other analytics package?

The directly-measured data from Alexa Certified Site Metrics counts visits and pageviews from real people, not traffic from spiders, web crawlers, or  other computers.

Here are some considerations:

  • If the Alexa Certify Code is not installed on every page of your website, then all traffic will not be counted.
  • Alexa filters out web crawlers and other machine-generated traffic.
  • To make sure that traffic is not double-counted, only traffic to the top, enclosing page is counted on pages that contain sub-components, ads, or widgets.
  • If your widgets or ads appear on other websites (IFRAMEs), that traffic is not counted as traffic on your website. Alexa only counts traffic when your website’s URL is in the browser address bar.
  • The date boundaries may be different.   Alexa’s dates are in UTC.
  • The Daily Data displayed on the Site Overview page is a 7 day average. Until your site’s metrics have been certified for 7 days, the average might appear low.
  • If a visitor to your website navigates to a new page before the Alexa certify code can run, that pageview will not be counted. For best performance, we recommend placing the Alexa Certify Code in the <head> section.
  • Alexa does not currently support tracking Facebook Instant Article traffic.

Note: Please make sure you are comparing the same metrics, for example Unique Visitors to Unique Visitors and Pageviews to Pageviews.

Also, every website analytics package makes different assumptions which affect the numbers that it reports. Some of the assumptions are related to determining the number of people who visited your website:

  • What traffic comes from web crawlers and how should it be counted?
    (Note: Many analytics packages that process log files inadvertently count traffic from web crawlers.)
  • What traffic is due to automated spam and shouldn’t be counted?
  • How often do people clear their cookies?
  • What percentage of people have javascript disabled?
  • How often do different people share the same computer?