Webalizer vs. Google Analytics

Has anyone noticed a difference between webalizer stats and google analytics?  I am finding significant varience between "unique visitors" in webalizer vs. google analytics.  I undertsand that webalizer is parsing log files, whereas google is being passed info via a script.
LVL 1
tmateosian1Asked:
Who is Participating?
I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

PhilHowCommented:
Unique over what period of time?  24 hours?, 10 days? 30 days?

Are the time slices calculated form the same time zone?  It the GA code on every page (it won't report 403, 404, or 500  errors as a hit unless you have custom error pages with the GA code.  Webalizer reports everything in the log.  There are many other variables.

The changes of getting the same result from both is just about zero.  They are two totally different approaches to stats generation.  Comaring them to confirm trends is about the only reconciliation that is possible.
0
tmateosian1Author Commented:
PhilHow:
I'm not looking for the exact cause, nor do I expect them to match, but rather looking for the reasons they can vary.  For instance I know that some script blockers will cause the GA script to not report.  Good call about the 403, 404, 500!  Please list as many *possible* reasons as you can think of.  Thanks.
0
cogboxerCommented:
Webalizer, being a log file analyzer, has to make certain assumptions about what is actually a unique visitor using time of request, IP address, UserAgent (browser, OS) etc.

Google Analytics, being a web-beacon type tracker, can actually cookie individual visitors, giving a much better "unique visitor" number. So, it's not surprising that they have significantly different numbers.
0
tmateosian1Author Commented:
cogboxer:
Yes that's a good point.  What happens if someone has disabled cookies?  I guess what I'm getting at is that webalizer provides a more favorable (i.e. higher) figure and I am looking for ways to explain the difference.  SO far I have some reasons why GA would be lower, and also some reasons why GA would be more accurate about uniqueness for those visitors it can track.  
0
cogboxerCommented:
With Google Analytics visitors with cookies disabled will not be tracked. Because Google Analytics uses first party cookies (cookies set and read by the same domain currently shown in your address bar) the number of real users that will block these cookies is small. And, at the same time this prevents Google Analytics from tracking visits from automated spiders and other systems that don't interpret JavaScript.

Webalizer will show all requests of the server recorded in the server logs. It doesn't actually interact with the browser at all. One benefit of this is that you can see how often certain elements of a page have been accessed--such as particular images, css files, PDFs, includes, and other non-page elements.

Whether Webalizer or Google Analytics would be lower would depend upon the assumptions set up in Webalizer. Personally, for a figure like unique visitors, I think Google Analytics will yield the more accurate figure.

I've found that clients can often find it frustrating when you can't give them a very simple "we generated X unique visitors to the site last month". So, I would pick a standard that you will rely on, then whenever possible implement that tracking tool early in any design/redesign/marketing process. Your before and after stats will be comparing apples to apples.

Here's a Google Analytics page that discusses this issue:
http://www.google.com/support/analytics/bin/answer.py?answer=27235&query=blocked+cookies&topic=&type=
0

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today
Web Development

From novice to tech pro — start learning today.