I thought the latest version of Opera supports all the HTML5 features, but it seems blogger.com does support it. I see a message at the top of the page mentioning "Your browser is no longer supported by Blogger. Some parts of Blogger will not work and you may experience problems. If you are having problems, try Google Chrome. | Dismiss" I hope in the future there will be a support for Opera browser as I like to use it for the purpose of development and testing. It will be nice if it's supported but if its not, it will be sad that I will have to post from a non supported browser.