How does duplicate Google Analytics tracking code affect a site?

Question

I have a site where I can see that the tracking code has been added twice (once in the Drupal GA module, and once added manually in the template file).

Both scripts are pointing to the exact same account.

What are the consequences of this? I am looking into the issue since the bounce rate seems to be extremely low over the last few months compared to usual. Would this be a reason for that, or is something else causing that issue?

Would double tacking code produce double the hits in Google Analytics?

Answer 1

The consequences of having two Google Analytics scripts, especially if they are pointing to the same UA-ID, is that you'll end up double counting pageviews, visits, etc. Do you have the option of removing one? If so, do that.

Answer 2

The double analytics code will affect bounce-rate and page-views, but it WILL NOT affect sessions (visits) as Irene wrote. The pages / session will definitely change since the pages are counted twice. The reason that sessions stay the same is that the user is still the same user, just with two page-views.

I am writing this after removing duplicate codes from a site and monitoring the changes.

Answer 3

A lot of metrics are affected by duplicated tracking code, including pageviews (which get inflated), bounce rate (which drops to almost 0) and many others.

I found this article detailing the full effects: https://www.houseofprogress.co/blog/google-analytics-duplicated-code-affected-metrics/ .

Answer 4

It does affect your pageviews duplicating em, but does not affect your sessions or users.