Why does AWStats show different numbers than Google Analytics?

Some customers who track visitors using AWStats (which we provide) also use Google Analytics, or other software that tracks statistics like a WordPress plugin.

These systems have a similar purpose, but measure things in different ways. Because of that, they can show different numbers. It’s important to understand what each is capable of tracking.

What’s the difference?

AWStats examines our Web server logs and counts every “hit” to any URL on your site. This includes “hits” to “404 not found” URLs that don’t exist and “hits” to URLs that aren’t Web pages (such as images that are hotlinked from other sites). It calculates “unique visitors” by checking whether the IP address of the hits is different.

On the other hand, Google Analytics, WordPress plugins, and similar systems only count “hits” to working HTML pages that you’ve added certain JavaScript code to. For example, they can’t normally count “404 not found” pages, or hotlinked images, or connections from browsers with JavaScript disabled, or visits from “spam harvesting robots” searching for e-mail addresses on your pages. Of course, if you’re interested only in human visitor behavior, that can be a blessing. Google Analytics also calculates unique visitors differently: it uses a “cookie” on the visitor’s browser to see if the same person visits twice, even if they use different IP addresses.

Each of these approaches has its strengths and weaknesses. If you have a large number of visitors to your site, the differences will often disappear into the noise. But if your site has a small number of visitors and some of those “visitors” are requesting pages that Google Analytics can’t see, the difference can be fairly large in percentage terms.

If you care about the difference, you need to think about what each is measuring and use the system that comes closest to what you care about.