Getting rid of flashing white page on your website

Today it's going to be a quick one, and I actually don't have a link this time, I just remember I had to deal with a flashing white page appearing for a split second on a black background website that obviously didn't look very good. Reading through a couple of articles, I learned that the cause of the issue is that I have used javascript on my website but the script itself was in the header. This could be anything, even your Google Analytics code. The solution: