Google’s site speed report can be a dangerous metric. I recently saw how Safari showed an upload time of 36 seconds. Not a number you would want to see. Besides being too high to be true, Safari doesn’t even support Google Analytics’ site speed report. So Safari should be zero.
It turns out that by digging in I found three important factors.
In this case Google analytics was reporting on Safari in apps. Not something you would expect since Safari should show zero.In some cases I have seen Google Analytics show Safari (not the apps) with high loading numbers even though it is not supportedIn all cases, GA uses very small samples so the data can be very skewed.
Make sure you look at the daily graph to make sure data points are reasonable.Increase your sample size by adding this code in your GA snippet right before ‘_trackpageview’ :“_gaq.push([‘_setSiteSpeedSampleRate’, 20]);” . You can replace the 20 with 100 if you want 100% sampling