Google Analytics visitor statistics

Is google's analytics tool accurate?

[netidme]

Hi,
I'm new to SEO, and webmaster world, so sorry if this question has been covered before...I am now using google analytics to track my website statistics, but I also ran web trends for 30 day free trial. The daily visit stats were approx 30% lower in google than web trends, does anyone know why this would be? Thanks

[PHeaven]

I have seen that too, guess it is because Analytics is using javascript and that prevents it from counting spam-robots, spiders, and search crawlers into the statistics.

WebTrends I think have hard trouble to filter out spiders/crawlers...

[Brett_Tabke]

An analytics program that analyzes log files is still the most accurate.

While a simple page counter (javascript or image tag), will always be slightly inaccurate. Numerous people will visit your site with images off or java script off, or by some other means that doesn't trigger the counter.

[centime]

I am not sure of this, but isn't web trends also a log analyser?

I was going to get a log analysis program till I found web trends . I also use GA as well

[HelenDev]

An analytics program that analyzes log files is still the most accurate.

This statement seems to directly contradict what Receptional posted in this thread [webmasterworld.com ]...

Javascript tagging is MUCH better for most people to use, probably correctly analysing 90-95% of human users, whilst (IMHO) even the best log tracking can miss 35% of users on busy sites (though much more accurate on quieter sites).

Care to elaborate?

[Brett_Tabke]

HelenDev, Dixon was talking about what is best for most people that want to track human visitors. Read farther up his post:

...client side tracking (usually denoted by java code on your web page which runs when a user loads the page) is disastrous at tracking robots, or working out if your webserver is getting too busy to cope.

and also read:

Here are 8 reasons why java tagging systems scew up measuring users:

> The daily visit stats were approx 30% lower in google
> than web trends, does anyone know why this would be? Thanks

Google uses a js or image tag, while web trends analyzes raw server log files. Google only looks at vistors that trigger the js/image counter, while Web Trends looks at every object it serves.

That doesn't say why there would be that much difference (30%) between the two. I would look deeper into it and figure out why there is that much difference. Mobile site aimed at devices that can't run javascript?

[HelenDev]

Thanks for the clarification Brett.

So would you say that logfiles are more accurate for tracking all traffics, bots and human, but page tagging is more accurate for tracking human visitors?

I know that there are some users/devices which browse with images/js turned off, but I would imagine that these are a reasonably small minority right? Unless your site is aimed particularly at these users of course.