Embedding Youtube Video on a website  can go a long way in helping a website make a video statement but one of the major issues is knowing how to make the video autoplay on page load. If you have spend time and money making a very good marketing video for your products or services,you would definitely like that to play immdiately the page loads . Lets not forget that videos have a very convincing effect customers and besides that people love videos.

To add auto play to your youtube embedd code, all you need to do is to edit the code and add ?autoplay=1  to the video url. Lets the following video embed code as an example.

Before

<iframe width="560" height="315" src="//www.youtube.com/embed/1N5THRSp4hM" frameborder="0" allowfullscreen></iframe>

After adding autoplay

<iframe width="560" height="315" src="//www.youtube.com/embed/1N5THRSp4hM?autoplay=1" frameborder="0" allowfullscreen></iframe>

Notice the addition there. May be this article here would explain better