Fast page load times are vital for websites. Internet users have a notoriously short attention span, and will leave if a site takes more than a few seconds to load. Before placing additional code onto a website, it’s important to determine whether that will effect page load times negatively.
If Google Analytics tracking code doesn’t load before a visitor leaves the site or clicks away from the page, the page data won’t show up in Google Analytics. You can compensate for this scenario by running web log analysis software in conjunction with Google Analytics.
Does Google Analytics Code Slow Down My Site?
Next, the code requests a 1×1 transparent image named __utm.gif. It attaches information in the query string of this file, and that’s how it sends information to Google Analytics. This file is requested with every pageview, but it is 35 bytes. Small enough to be insignificant, regardless of what speed your Internet connection is. It might take 1/100 or 1/50 of a second to load.
With previous versions of Google Analytics, Google recommended placing the tracking code at the very end of the body just before the closing