HTML5 video
Support for HTML5 video has been steadily increasing. In June 2013, Netflix added support for HTML5 video. In January 2015, YouTube switched to using HTML5 video instead of Flash by default. In December 2015, Facebook switched from Flash to HTML5 for all video content.
VP9
VP9 is implemented in these web browsers:
Internet Explorer and Apple Safari are missing VP9 support completely.
In March 2016 an estimated 65 to 75% of browsers in use on desktop and notebook systems were able to play VP9 videos in HTML5 webpages, based on data from StatCounter.