If you’d like your embedded video to autoplay or loop, go to the video you'd like to embed and click the "Share" button in the video player. In the window that opens, click the "Show options" link, and check the corresponding boxes next to "Loop this video," "Autoplay this video," or both. You can then copy the embed code.
You can also do this manually by adding the following parameters into your embed code:
loop=1
autoplay=1
If you have more than one video autoplaying on a particular page, you will also need to include this parameter:
autopause=0
So, for example, if you were embedding two autoplay, looping, videos on a page, the embed code for each would look like this:
<iframe src="https://player.vimeo.com/video/12345?autoplay=1&loop=1&autopause=0" width="500" height="281" frameborder="0" webkitallowfullscreen mozallowfullscreen allowfullscreen></iframe>
Important: Please be aware that autoplay and loop will not work on most mobile devices.