Google has announced plans to slowly kill off support in its Chrome browser for most websites that use Adobe's Flash by December in favor of HTML5 sites.
While the use of Flash on websites has diminished in the past few years, there are still some sites that use it. In a blog post. Google stated:
Today, more than 90% of the Flash on the web loads behind the scenes to support things like page analytics. This kind of Flash slows you down, and starting this September, Chrome 53 will begin to block it. HTML5 is much lighter and faster, and publishers are switching over to speed up page loading and save you more battery life. You'll see an improvement in responsiveness and efficiency for many sites.
HTML5 will become the default way to view websites with the release of Chrome 55 in December, according to Google. The only exceptions will be sites that only use Flash, in which case the browser will prompt used to enable Flash when they visit the site.