Go to a YouTube video – on YouTube.com
- Click “Share” then “Embed” and grab the code
Default Embed Code:
I changed the default width="560" at the start to width="100%"
Also added style="max-width: 600px;" - after allowfullscreen:
I can’t show an example unfortunately, as my Free WordPress.com blog doesn’t allow to add any code. The embed above isn’t fully responsive.